Identity is the set of properties, relationships, continuity rules and recognised identifiers that make an entity itself rather than another entity. If you are asking “what is identity?”, the clearest answer depends on the domain. Personal identity concerns what makes a person the same person across time. Digital identity concerns accounts, credentials and attributes. Biological identity concerns organisms, cells and lineages. Database identity concerns unique records. Philosophy asks the deepest version: what makes anything one and the same thing despite change?
A complete explanation of identity must distinguish identity from similarity, names and categories. Two objects can look identical while remaining two different objects. One person can use several names while remaining one person. A category such as “student” tells us what kind of entity someone is in a context, but it does not uniquely identify which student. Identity therefore requires rules for distinction and persistence, not merely a descriptive label.
This guide explains identity from first principles: numerical and qualitative identity, persistence through time, personal and social identity, biological identity, legal identity, digital identity, identifiers, authentication, entity resolution, provenance, object identity, mathematical identity, versioning, privacy and artificial intelligence. The goal is a durable operating model: define the type of entity, decide what counts as sameness, use stable evidence to distinguish it from alternatives, and preserve continuity without pretending that every attribute must remain unchanged.
What Is Identity? A Short Definition
Identity is the set of properties, relationships, continuity rules or recognised attributes by which something is treated as the same entity rather than another. The concept applies to people, organisms, objects, organisations, data records, brands, mathematical expressions and digital accounts. Identity therefore answers a fundamental question: what makes this thing this thing, and what allows us to recognise it across time and change?
Identity and Sameness
Identity is stronger than similarity. Two books can be identical in edition and appearance yet remain two distinct physical copies. Sameness can mean same kind, same properties or the very same individual. Philosophers call the last relation numerical identity: one thing is numerically identical only with itself, even when another thing resembles it perfectly.
Qualitative Identity
Qualitative identity means sharing properties. Two manufactured bolts can have the same dimensions, material and finish, making them qualitatively identical for many purposes. Yet they still occupy different places and have different histories. This distinction matters in engineering, law and databases because interchangeable properties do not automatically establish that two records refer to the same underlying entity.
Numerical Identity
Numerical identity means being one and the same entity. The morning star and evening star were once treated as different celestial objects but are both appearances of Venus; two descriptions can therefore refer to one numerically identical object. Identity questions often involve discovering whether different names, records or observations concern one entity or several.
Identity Over Time
Persistence asks how an entity remains the same while changing. A person ages, a company changes staff and a ship receives replacement parts. Identity through time therefore depends on continuity criteria. Different kinds of things use different criteria: biological continuity, legal continuity, functional continuity or causal history can each matter.
Change and Identity
Something can change without becoming a different entity, but not every change is identity-preserving. Repainting a bicycle usually preserves identity; melting it into scrap may not. The boundary depends on what kind of object it is and which continuity conditions define it. Identity therefore interacts with change rather than opposing it.
The Ship of Theseus
The Ship of Theseus thought experiment asks whether a ship remains the same ship after every plank is gradually replaced. If the removed planks are rebuilt into another ship, which one is the original? The puzzle reveals that ordinary identity judgments combine material continuity, structural continuity and causal history in ways that can conflict.
Material Continuity
Material continuity treats persistence of physical substance as important. A gemstone can retain identity because the same material persists. Yet living organisms constantly exchange matter, and repaired machines replace parts, showing that material continuity cannot be the only identity rule for every entity.
Structural Continuity
Structural continuity focuses on organisation. A pattern can persist even when individual components change. Organisms, organisations and software systems often retain identity through stable relationships among changing parts. Structure therefore provides one route for understanding persistence without requiring fixed material composition.
Functional Continuity
Functional continuity treats identity as connected to what the system does. A repaired engine remains the same engine in practical use because its role and causal history continue. But function alone is not always sufficient: two devices can perform the same function while remaining distinct objects.
Causal Continuity
Causal continuity links present states to earlier states through an appropriate chain of events. A restored painting remains connected to its earlier physical and historical existence. In digital systems, a record migrated between servers can preserve identity when the transfer process maintains traceable continuity rather than merely copying similar data.
Identity and Boundaries
To identify something, we need a boundary separating it from its environment or peers. Boundaries can be physical, conceptual, legal or informational. A cell membrane defines a biological unit; a corporate charter defines an organisation; a database key defines a record. Poorly chosen boundaries create identity confusion.
Identity and Properties
Properties help identify entities, but most properties are not unique. Height, colour, age and location can match across many objects or people. Identification therefore usually requires combinations of properties plus context. Strong identity systems distinguish descriptive attributes from identifiers specifically designed to separate entities.
Names
Names are labels used to refer to entities. They are convenient but not guaranteed unique or permanent. Multiple people can share a name, one person can have several names and organisations can rename themselves. A name is therefore an identity aid, not identity itself.
Identifiers
An identifier is a label intended to distinguish an entity within a defined system. Student numbers, serial numbers and database IDs are examples. Good identifiers have clear scope and persistence rules. An identifier can remain stable even when descriptive attributes such as address or job title change.
Unique Identifiers
A unique identifier is designed so no two entities in the relevant domain share the same value. Uniqueness always has a scope: a local customer number may be unique within one company but not globally. Good data architecture states the scope rather than assuming an ID is universally unique.
Identity in Databases
Databases need entity identity so records can be updated, linked and deduplicated. Primary keys identify rows; natural keys use meaningful real-world attributes; surrogate keys use system-generated values. The choice affects stability, privacy and interoperability. A record key identifies a representation, which must still be linked correctly to the real entity.
Entity Resolution
Entity resolution determines whether separate records refer to the same real-world entity. Misspelled names, changed addresses and duplicate accounts make this difficult. Matching systems use combinations of identifiers and attributes, but false matches and missed matches have different consequences. High-stakes identity resolution requires careful thresholds and review.
Deduplication
Deduplication removes or merges records representing the same entity. It sounds simple until records differ slightly or contain conflicting fields. Good deduplication preserves provenance and avoids merging genuinely distinct entities merely because their names resemble each other.
Identity and Reference
Reference is the relationship between a symbol, name or record and the entity it denotes. Identity problems often arise when different references are mistaken for different things or one reference is reused for several things. Clear reference rules make communication and data integration more reliable.
Personal Identity
Personal identity asks what makes a person the same person across time. Bodies change, memories fade and roles shift, yet people ordinarily experience continuity. Philosophical theories emphasise bodily continuity, psychological continuity, memory, narrative or combinations of these. No simple everyday criterion solves every edge case.
Bodily Continuity
Bodily theories connect personal identity to continuity of the living organism or brain. The person persists because the same biological life continues through change. This approach fits many ordinary cases but raises difficult questions in hypothetical scenarios involving transplantation, duplication or radical neural replacement.
Psychological Continuity
Psychological-continuity theories emphasise connected memories, intentions, character and mental states. A future person is continuous with an earlier person when the relevant psychological relationships are preserved. Memory cannot be the whole story because memories can be inaccurate, lost or artificially reproduced.
Memory and Identity
Memory contributes strongly to the sense of self by connecting present experience with a personal past. Autobiographical memory supports narrative continuity. Yet people remain themselves during sleep, temporary amnesia and periods they cannot remember. Memory is therefore an important component of personal identity without being the sole criterion.
Narrative Identity
Narrative identity describes the self partly through an organised story linking experiences, commitments and aspirations. People reinterpret their histories as they learn and change. Narrative is powerful because it gives events meaning, but a self-story can also be incomplete or mistaken, so narrative identity should not be confused with objective biography.
Identity and the Body
Body ownership, appearance and physical capability contribute to personal identity. Illness, injury and development can change the way a person experiences the self. Biological continuity provides stability while embodied experience changes, illustrating how identity can persist through substantial transformation.
Identity and Agency
Agency is the capacity to act intentionally. People often connect identity with choices, commitments and responsibility. Yet identity should not be reduced to isolated choices because circumstances, development and social context also shape action. A useful account allows both continuity and change.
Social Identity
Social identity refers to aspects of self-understanding connected to membership, roles and relationships within groups. Family role, occupation, language community, school, profession or nationality can contribute to social identity. Individuals can participate in several groups at once, so social identity is usually plural rather than one total label.
Roles
Roles are socially recognised positions with expectations, such as teacher, parent, student or manager. A role can strongly shape behaviour without exhausting personal identity. People move between roles and sometimes experience conflict when two roles demand incompatible actions.
Group Identity
Group identity arises when people recognise shared membership and characteristics. Groups can provide belonging, norms and coordination. Group labels are useful at the collective level but should not be used to assume that every member has identical beliefs, abilities or preferences.
Cultural Identity
Cultural identity connects people with languages, traditions, practices, histories and communities. It can be inherited, learned, chosen, mixed or transformed. Cultural identities are dynamic because cultures themselves change through migration, technology, exchange and generational development.
Professional Identity
Professional identity is the way a person understands themselves within a field of work, including standards, skills, responsibilities and community membership. Training often develops professional identity alongside technical knowledge. Strong professional identity can support ethical standards, but it should remain open to evidence and changing practice.
Organisational Identity
Organisational identity concerns what members understand to be distinctive and enduring about an organisation. Mission, history, practices and culture contribute. Rebranding can change appearance without changing underlying identity; mergers or strategic shifts can alter the deeper continuity. Organisational identity matters because it shapes decisions and employee expectations.
Brand Identity
Brand identity is the designed system of names, visual elements, tone and associations used to distinguish an offering or organisation. Logos and colours are only part of it. A brand’s perceived identity also depends on behaviour and customer experience, which means declared identity and experienced identity can diverge.
Legal Identity
Legal identity is the status through which a person or organisation is recognised within legal and administrative systems. Names, registrations and official records help connect rights and obligations to the correct entity. Legal identity is system-dependent: rules specify how identities are created, changed, inherited or dissolved.
Corporate Identity
A corporation can persist even when shareholders, directors and employees change because law recognises organisational continuity. Corporate identity is therefore an example of identity maintained by rules, records and institutions rather than by stable human membership or physical material.
Identity Documents
Identity documents provide evidence linking a person to an officially recognised record. Documents are credentials, not the person themselves. Secure systems therefore verify authenticity, validity and appropriate matching rather than treating possession of a document as infallible proof in every context.
Digital Identity
Digital identity is the collection of identifiers, credentials, attributes and activity records through which a person, device or organisation is represented in digital systems. One person can have many digital identities across platforms. Good identity systems distinguish authentication, authorisation and profile information.
Usernames
A username is a label used to identify an account within a system. It may be public, changeable or reused after deletion depending on platform rules. Usernames are convenient references but weak evidence of real-world identity unless combined with stronger verification.
Passwords and Credentials
Credentials provide evidence that an actor is entitled to claim an identity. Passwords, security keys, certificates and biometric factors are examples. Credentials should be protected because theft allows impersonation. Secure identity design assumes identifiers can be public while authenticators must resist unauthorised use.
Authentication
Authentication checks whether a user or system is the entity it claims to be. Passwords, one-time codes, cryptographic keys and biometrics are authentication mechanisms. Strong authentication reduces impersonation but does not decide what an authenticated user is allowed to do.
Authorisation
Authorisation determines which actions an authenticated identity may perform. A user can be correctly authenticated yet lack permission to access a record or change a system setting. Separating authentication from authorisation prevents “known identity” from being mistaken for unlimited access.
Multi-Factor Authentication
Multi-factor authentication combines evidence from different categories, such as something known, possessed or inherent. Multiple independent factors reduce the chance that one stolen credential compromises the account. Independence matters: two passwords are not the same as two genuinely different factors.
Biometrics
Biometrics use measurable biological or behavioural traits such as fingerprints, facial features or voice. They can support authentication but are probabilistic rather than perfect. Unlike a password, a biometric characteristic cannot easily be replaced after compromise, so secure systems protect templates and provide alternative recovery methods.
Digital Signatures
Digital signatures use cryptography to connect a message or transaction with a private signing key. Verification provides evidence that the signed data have not been altered and that the holder of the corresponding key authorised the signature. A digital signature authenticates a key relationship; institutional processes connect that key to a real-world identity.
Certificates
Digital certificates bind public keys to named entities under a trust system. Certificate authorities and organisational processes support that binding. Certificates illustrate that digital identity depends on both cryptography and governance: mathematics protects the link, while institutions decide whom the link represents.
Identity Federation
Federated identity allows one trusted identity provider to authenticate users for multiple services. It reduces the need for separate passwords but creates dependency on the identity provider. Federation therefore trades convenience for concentration risk and requires clear trust boundaries.
Single Sign-On
Single sign-on lets users authenticate once and access several connected services. It improves usability and can strengthen central security controls. A compromised central account can also expose multiple services, so strong authentication, session management and monitoring become especially important.
Identity and Privacy
Identity systems often collect attributes that can expose sensitive information. Privacy-conscious design gathers only what is necessary for the purpose. Proving “over 18” may not require revealing exact birth date. Selective disclosure and data minimisation reduce the amount of identity information at risk.
Anonymity
Anonymity means a person’s real-world identity is not known or linked to an action within the relevant context. It can protect privacy and safety, but it can also reduce accountability. Anonymity is not absolute: technical traces or external datasets may allow re-identification.
Pseudonymity
Pseudonymity uses a persistent alternative identifier rather than a direct real-world name. A pseudonym can support reputation and continuity while limiting immediate disclosure. It differs from full anonymity because actions under the pseudonym can be linked together, and an authorised party may retain a mapping to the underlying identity.
Re-Identification
Re-identification links supposedly anonymous data back to specific individuals using combinations of attributes or external information. Removing names alone is often insufficient. Privacy risk therefore depends on what other data exist and how uniquely the remaining attributes describe people.
Device Identity
Devices need identities so networks and services can distinguish legitimate equipment from unknown or impersonated systems. Serial numbers, cryptographic certificates and hardware-backed keys can contribute. A device identity should remain separate from the human user identity because one device can serve several people and one person can use many devices.
Machine Identity
Modern infrastructure contains software services, workloads and automated agents that must authenticate to one another. Machine identity uses keys, certificates, tokens and workload identities. Poor machine-identity management can create invisible long-lived credentials with broad access, making automated identity lifecycle control essential.
Identity in Cybersecurity
Cybersecurity treats identity as a control plane for access. Attackers often target accounts because valid credentials can bypass perimeter defences. Identity security therefore includes strong authentication, least privilege, credential rotation, anomaly monitoring and rapid revocation when compromise is suspected.
Identity Theft
Identity theft occurs when someone uses another person’s identifying information or credentials for unauthorised activity. It can involve financial fraud, account takeover or impersonation. Recovery is difficult because identity data such as birth dates may be persistent, so prevention emphasises secure credentials, verification and monitoring.
Identity Proofing
Identity proofing establishes that a claimed identity corresponds to a real person or entity at enrolment. It can use documents, databases, in-person checks or remote verification. Strong proofing reduces fraudulent account creation but must balance security, accessibility and privacy.
Identity Lifecycle
Identities have lifecycles: creation, activation, changes in attributes or roles, suspension and termination. Access should change when jobs, responsibilities or relationships change. Orphaned accounts and outdated permissions are common security risks because the identity record persists after the legitimate need disappears.
Object Identity
Physical objects need identity in manufacturing, logistics, maintenance and law. Serial numbers, tags and provenance records distinguish one unit from another. Object identity can persist through repairs while components change, provided the continuity rules for that asset remain clear.
Product Identity
Product identity can refer to a model, batch or individual item. A barcode may identify a product type while a serial number identifies one unit. Confusing these levels causes inventory and warranty errors. Good systems state whether an identifier denotes a category, lot or unique object.
Provenance
Provenance records the origin and history of an entity. It strengthens identity claims for artworks, scientific samples, data and products by showing a chain of custody or transformations. Provenance helps distinguish an original from a copy and reveals whether continuity has been maintained.
Biological Identity
Biological identity can refer to an organism, cell line, species or genetic individual. The criteria differ by level. A multicellular organism maintains identity despite cellular turnover, while a clonal cell line may preserve a lineage even as individual cells divide. Biology therefore offers many examples of persistence through replacement.
Genetic Identity
DNA profiles can distinguish individuals with high probability under specified methods, but genes are not the whole of identity. Identical twins can share extremely similar genomes yet remain distinct persons with separate bodies, histories and experiences. Genetic identification is powerful evidence about biological relationship, not a total description of a person.
Species Identity
Species identity concerns classification of organisms into biological groups. Species concepts use reproductive relationships, evolutionary lineages, morphology or ecology depending on context. Edge cases such as asexual organisms and hybridisation show that natural categories can have fuzzy boundaries even when the underlying biological patterns are real.
Cell Identity
Cells develop identities through gene expression, molecular state, position and developmental history. Two cells can contain nearly identical DNA yet function as neurons or muscle cells because different genes and regulatory programmes are active. Cell identity is therefore an organised state, not only a genome sequence.
Identity in Mathematics
In mathematics, identity has precise meanings. An identity equation is true for all values in its domain, such as a trigonometric identity. The identity element leaves other elements unchanged under an operation, such as zero for addition or one for multiplication. Mathematical usage shows how one word can acquire rigorous domain-specific definitions.
Identity Equations
An identity equation differs from an equation true only for particular solutions. For example, expanding a squared binomial produces an identity because both expressions agree for every allowed value. Recognising identities allows algebraic expressions to be transformed without changing the underlying function.
Identity Elements
An identity element is an element that leaves another element unchanged under an operation. Zero is the additive identity because a + 0 = a. One is the multiplicative identity because a × 1 = a. Abstract algebra generalises the idea to groups and other structures.
Identity in Logic
Logic and philosophy study the relation of self-identity: every object is identical to itself. Identity also supports substitution under appropriate conditions. But language can make co-reference difficult, as when two names turn out to refer to the same object. Logical identity separates the entity from the words used to denote it.
Identity in Programming
Programming languages distinguish value equality from object identity. Two objects can contain equal data while occupying different memory locations or carrying different references. Bugs arise when programmers assume that equality of content means the references denote the same object.
Identity in Distributed Systems
Distributed systems duplicate data across machines, creating difficult questions about which copy represents the authoritative entity and how updates are reconciled. Stable identifiers, version numbers and consistency rules help preserve identity through replication and migration.
Identity and Versioning
Versioning records how an entity changes while preserving lineage. A document can have many versions that belong to one continuing work. Software releases can share project identity while differing substantially in code. Version systems make change explicit rather than overwriting history and losing continuity evidence.
Copies and Originals
A copy can be qualitatively identical to an original without being numerically identical. Digital copying complicates intuition because two files may contain exactly the same bits. Their identity may then depend on path, record, ownership, provenance or hash, depending on the system’s purpose.
Identity and Authenticity
Authenticity asks whether something genuinely has the origin, authorship or nature claimed for it. Identity asks what entity it is. An artwork can be correctly identified as a particular painting yet have disputed attribution. Authentication therefore uses identity plus provenance and evidence about origin.
Identity and Classification
Classification places entities into categories; identity distinguishes entities within or across those categories. Knowing that an animal is a dog does not tell us which dog it is. Good information systems maintain both class information and individual identity because the questions they answer differ.
Identity and Similarity
Similarity measures resemblance rather than sameness. Search engines, face matching and recommendation systems often compute similarity scores. A high score can suggest a possible identity match but should not automatically be treated as proof, especially when false matches have serious consequences.
Identity and Difference
Identity becomes meaningful through difference. To recognise one entity, a system must distinguish it from alternatives. Features useful for identity are therefore those that remain stable for the entity while varying enough across entities. This balance explains why identification systems combine persistent identifiers with contextual attributes.
Identity and Context
The same identifier can refer to different entities in different contexts. “101” might be a room, course, customer or error code. Identity always has a namespace or domain, even when that namespace is implicit. Explicit context prevents collisions and mistaken assumptions of global uniqueness.
Identity and Namespaces
A namespace defines the scope in which names or identifiers are interpreted. Domain names, programming modules and database systems use namespaces to allow the same local label without confusion. Namespaces are fundamental because global uniqueness is expensive and often unnecessary.
Identity and Time
Identifiers can change, be reused or expire. Time therefore matters to identity. A telephone number may belong to one person today and another later. Historical systems should store effective dates so an identifier is not assumed to refer to the same entity across all periods.
Identity and Location
Location can help identify an entity but is rarely sufficient. Stores, devices and people move, while many entities can occupy one location at different times. Location is best treated as an attribute with time context rather than as permanent identity.
Identity and Relationships
Relationships help establish identity. Family ties, ownership chains, network connections and organisational roles can distinguish entities with similar attributes. Graph-based identity systems use relationship patterns alongside direct identifiers to improve entity resolution.
Identity and Reputation
Reputation is an accumulated evaluation associated with an identity. It depends on continuity: ratings are useful only if past actions can be linked to the same actor. Strong identity increases accountability, while pseudonymous continuity can sometimes preserve reputation without revealing a legal name.
Identity and Trust
Trust depends partly on confidence that the entity acting now is the same entity previously evaluated or authorised. Authentication, provenance and reputation all support this continuity. Identity alone does not prove trustworthiness; it makes past evidence attachable to the correct entity.
Identity and Responsibility
Responsibility requires linking actions to agents or systems. Audit logs, signatures and chain-of-custody records help establish who or what performed an action. Good accountability preserves identity evidence while respecting privacy and avoiding collection unrelated to the legitimate purpose.
Identity and Change
Identity systems must allow legitimate change. People change names, organisations restructure and devices are replaced. A rigid system that equates identity with one unchangeable attribute can exclude legitimate users. Better systems preserve continuity through controlled updates and historical records.
Identity and Replacement
Replacement tests identity rules. If a component fails and is replaced, the larger system may retain identity. If every component is eventually replaced, causal continuity or legal records may still preserve it. Identity often belongs to an organised history rather than one immutable material core.
Identity and Mergers
When organisations merge, identity becomes partly legal and partly social. A new entity may inherit contracts, brands or histories from predecessors. Data systems must decide whether to preserve old identifiers, create a new identity or maintain explicit predecessor-successor relationships.
Identity and Splits
When one organisation, dataset or biological lineage splits into two, both successors can inherit aspects of the original history. Identity can branch. Systems that assume one entity has exactly one future continuation may need special rules for such cases.
Identity and Artificial Intelligence
AI systems raise identity questions about models, versions, agents and generated content. Two deployed copies of the same model weights can be functionally similar but remain distinct running systems. An AI service updated over time can retain product identity while its internal model changes substantially.
Model Identity
A machine-learning model can be identified by architecture, weights, training run, version and configuration. Naming only the model family is insufficient when reproducibility matters. Exact model identity is important for safety investigations because two versions with the same public name can behave differently.
Agent Identity
Autonomous software agents may need persistent identities so actions, permissions and logs remain attributable. Agent identity should distinguish the underlying model from the particular agent instance and the human or organisation responsible for deployment. Clear separation reduces confusion about accountability.
Generated Content Identity
Generated images, text and code can be copied and transformed easily. Provenance standards and content hashes can help track versions, though editing changes hashes. Identity of digital content may therefore require a history of transformations rather than one permanent byte sequence.
Identity and Education
Education shapes identity by developing knowledge, roles and self-concepts. Students can begin to see themselves as readers, scientists, musicians or problem-solvers through successful practice. Educators should avoid turning temporary performance into fixed identity labels because capability changes with instruction and experience.
Identity and Self-Efficacy
Self-efficacy is belief in one’s capability for a specific task. It can influence identity but is not identical to it. A student may think “I am bad at mathematics” after repeated difficulty, converting performance evidence into a broad identity claim. Targeted success can repair both skill and self-concept.
Identity and Labels
Labels simplify communication but can become dangerous when they freeze a dynamic person or system into one category. “Beginner”, “expert”, “at risk” or “high performer” may describe evidence under conditions rather than permanent essence. Good use of labels preserves context and revisability.
Identity and Ethics
Identity systems affect privacy, inclusion, access and power. Verification rules can exclude people who lack standard documents; excessive tracking can remove anonymity unnecessarily. Ethical identity design collects only what is required, provides correction mechanisms and makes consequential matching errors appealable.
Common Misconceptions About Identity
Identity is not the same as name, appearance, category or one permanent attribute. Two things can be very similar yet distinct, and one entity can change substantially while remaining continuous. Digital identity is not only a username, genetic identity is not a complete person, and social identity does not determine every individual’s beliefs or behaviour.
A Practical Identity Checklist
Ask what type of entity is being identified and within which domain. Decide whether the task requires class membership, unique individual identity or continuity through time. Identify stable identifiers, supporting attributes, provenance and update rules. Then consider collisions, duplicates, privacy, false matches and what happens when identity legitimately changes.
How to Design Identity Systems
Start with the minimum identity claim needed for the task. Use stable identifiers separate from mutable attributes, define namespaces and lifecycle rules, protect credentials and preserve audit trails. For high-stakes matches, combine independent evidence and provide human review or recovery paths instead of assuming one automated score is infallible.
Frequently Asked Questions About Identity
What is identity in simple terms? Identity is what makes an entity recognisably itself rather than another. Is identity the same as a name? No; names are references and may not be unique. Can identity change? Attributes can change while continuity persists. What is digital identity? It is the representation of a person, device or organisation through identifiers, credentials and attributes in digital systems.
Authoritative Starting Points
Philosophy texts on personal identity and persistence examine numerical identity, continuity and the Ship of Theseus. Database and cybersecurity references explain identifiers, entity resolution, authentication and digital identity. Biology provides examples of identity across organisms and cells, while law shows how institutional rules create recognised identity for people and organisations.
What Is Identity? The Complete Idea
Identity is the structure that lets us say this entity is this one, not another, and that it remains connected to earlier states through relevant continuity. Different domains use different identity criteria: bodies, memories, causal history, legal records, cryptographic keys, database identifiers or organisational lineage. Strong identity reasoning always asks three questions: what kind of thing is this, what distinguishes it now, and what preserves or changes its identity through time?