Key AZ-204 terms in plain English. Knowing what each service is for - and when to choose it over a similar one - is exactly what the exam tests.
| Term | Definition |
|---|---|
| Azure Functions | A serverless, event-driven compute service that runs small pieces of code (triggered by HTTP, timers, queues and more) without managing servers. |
| Trigger | The event that starts an Azure Function, such as an HTTP request, a timer, or a new message on a queue. |
| Binding | A declarative connection between a Function and a service, used to pass data in or out without writing connection code. |
| App Service | A managed platform for hosting web apps and APIs, with features like deployment slots for staged releases. |
| Deployment slot | A live staging environment in App Service that lets you deploy and test, then swap into production with no downtime. |
| Container Apps | A serverless container service for running microservices and containerised apps without managing the underlying cluster. |
| Azure Container Instances | A service for running a single container quickly without orchestration; useful for simple or short-lived workloads. |
| Cosmos DB | A globally distributed, multi-model NoSQL database with tunable consistency and low-latency access. |
| Consistency level | A Cosmos DB setting that trades off data freshness against latency and availability, from strong to eventual. |
| Partition key | The property Cosmos DB uses to distribute data across partitions; choosing it well is key to performance and scale. |
| Blob storage | Azure object storage for unstructured data such as files, images and backups, organised into containers. |
| Access tier | A Blob storage setting (hot, cool, archive) that trades storage cost against access cost and retrieval time. |
| SAS token | A Shared Access Signature: a time-limited, scoped token granting access to a storage resource without sharing the account key. |
| Microsoft Entra | Azure’s identity service (formerly Azure Active Directory) used to authenticate users and applications. |
| Access token | A credential issued after authentication that an app presents to access a protected API or resource. |
| Key Vault | An Azure service for securely storing and accessing secrets, keys and certificates. |
| Managed Identity | An identity managed by Azure that lets a resource authenticate to other services without storing credentials in code. |
| API Management | A service to publish, secure, throttle and monitor APIs behind a single gateway. |
| Event Grid | A service for routing discrete events (such as a file uploaded) to handlers in an event-driven architecture. |
| Event Hubs | A high-throughput service for ingesting large streams of telemetry or event data. |
| Service Bus | An enterprise messaging service with queues and topics for reliably decoupling components. |
| Queue Storage | A simple, durable message queue for decoupling parts of an application. |
| Application Insights | An Azure Monitor feature that collects telemetry to monitor app performance and diagnose problems. |
| Azure Cache for Redis | An in-memory cache used to speed up applications by storing frequently accessed data. |
| CDN | A Content Delivery Network that caches content at edge locations to reduce latency for users. |