Identity
Identity is the property or representation by which an entity is distinguished and recognized as that particular entity.
Azure Security
An identity is a distinct representation of a user, application, service, or other entity that can be authenticated and authorized.
- How it is used
- Establishes the primary perimeter for securely accessing Azure services and performing actions on resources.
- How deep it goes
- Explains identity attributes, authentication, creation, and layered controls through Azure CLI and Azure IAM services.
- Examples
- Uses a user created with Azure CLI, suspicious login detection, password changes, phishing, and lateral movement scenarios.
- What you can do after
- Operate/configure user identities and layered Azure controls for authentication, authorization, privileged access, and credential management.
Software Security for Developers
User identity is the identity of the human or system entity that initiates a request chain.
- How it is used
- Frames request chains around the initiating user and the services acting on that user’s behalf.
- How deep it goes
- Defines user identity, distinguishes it from service identity and authentication, and explains propagation limits across protocols.
- Examples
- Uses customers, employees, API consumers, service call chains, spoofed headers, ID tokens, and tenant-specific claims.
- What you can do after
- Evaluate request designs by separating the initiating user from calling services and checking whether identity claims are authenticated.
Read how Software Security for Developers explains identity →
Java Persistence with Spring Data and Hibernate epub
Object identity is the property by which two object references are the same when they refer to the same object instance.
- How it is used
- Distinguishes references to one managed entity from separate instances representing the same database row.
- How deep it goes
- Works through Java comparisons and persistence-context lifecycle, but does not provide an implementation of custom equality.
- Examples
- Compares repeated entity lookups across two persistence contexts and tests the resulting references in a HashSet.
- What you can do after
- Diagnose/debug with it when reference comparisons or Set sizes differ after entities are loaded in separate persistence contexts.
Read how Java Persistence with Spring Data and Hibernate epub explains identity →
Authorization in Action
Identity is the notion of what makes an entity recognizable as itself, understood in this section through attributes or an underlying entity representation.
- How it is used
- Supports digital relationships, access control, personalization, and dynamic authorization by supplying recognizable entities and contextual signals.
- How deep it goes
- Defines identity functionally, explains relationship properties and authorization dependencies, but defers authentication mechanics and detailed authorization treatment.
- Examples
- Uses a café kiosk, the Target breach, ACME identity systems, multi-tenant C³, and principal–subject delegation to ground identity.
- What you can do after
- Evaluate identity inputs for authorization by distinguishing entities, relationships, attributes, identifiers, and confidence.
Clojure: The Essential Reference
Object identity is the property of an object being the specific allocated instance referenced by a value rather than merely an object with equal contents.
- How it is used
- Distinguishes one allocated instance from another when value equality cannot identify a particular reference.
- How deep it goes
- Defines the two-argument contract, arity failure, sentinel use, bindings, and interning surprises without detailing runtime allocation internals.
- Examples
- Demonstrates shared bindings, queue sentinels, cached values, independently constructed numbers, and basic-type interning.
- What you can do after
- Apply it via identical? to recognize a unique sentinel or verify that two bindings reference one instance.
Read how Clojure: The Essential Reference explains identity →
Get Programming: Learn to code with Python
Object identity is the property that distinguishes one particular Python runtime object from every other object.
- How it is used
- Distinguishes separate objects when variables or data structures hold similar values.
- How deep it goes
- Defines identity as unique and stable while an object exists, then demonstrates it with id() and printed locations.
- Examples
- Uses reassigned integers, Circle objects, Stack objects, and repeated versus distinct printed locations.
- What you can do after
- Diagnose/debug with it: use id() and printed object locations to tell separate objects from repeated references.
Read how Get Programming: Learn to code with Python explains identity →
React Hooks in Action: With Suspense and Concurrent Mode
Function identity is the property by which a function value is distinguished from other function values, including whether it remains the same value across renders.
- How it is used
- Uses function identity to control effect reruns and stabilize functions passed as component props.
- How deep it goes
- Explains render-time redefinition, dependency comparison, and useCallback stabilization through a worked fetch-loop example.
- Examples
- Demonstrates selected bookables, custom validation, timestamp enhancement, repeated network requests, and a useCallback-based updater.
- What you can do after
- Apply it via useCallback to keep function props stable and prevent unintended effect reruns.
Read how React Hooks in Action: With Suspense and Concurrent Mode explains identity →
100 Java Mistakes and How to Avoid Them
Reference identity is the property of two references denoting the same object instance, regardless of object content.
- How it is used
- Guides choosing collection semantics when mutable objects serve as map keys or set elements.
- How deep it goes
- Explains reference-based comparison, contrasts mutable-key hazards, and names identity-based collection implementations.
- Examples
- Uses a mutable list in a HashSet and recommends IdentityHashMap-based map and set alternatives.
- What you can do after
- Apply identity semantics through IdentityHashMap and its set adapter, while preventing mutation-related lookup failures.
Read how 100 Java Mistakes and How to Avoid Them explains identity →
Related concepts
- service identitycontrasts with · A service identity is an identifiable principal representing an application service in authentication and authorization decisions.
- authorization decisionused by · An authorization decision determines whether a principal is permitted to access a resource or perform an action under applicable permissions or policy.
- valuecontrasts with · A value is the content, quantity, information, or worth attributed to an entity, property, expression, or outcome.
- attributehas part · An attribute is a named property, value, or piece of information associated with an entity, object, or program element.
- service principalincludes · A service principal is a nonhuman application or service identity that authenticates and receives authorized access to resources.
These guides are generated from the text of Manning books by Manning's knowledge graph and link to the sections they draw on. The full books are available on liveBook and at manning.com.