Study Azure AZ-204 Containers: key concepts, common traps, and exam decision cues.
This lesson covers the first runtime choice AZ-204 tests in the compute lane: when a containerized solution is the right shape, how the image gets built and published, and whether Azure Container Instances or Azure Container Apps is the better hosting target.
Container registry: Managed store for versioned container images that deployment services can pull from consistently.
Container App revision: Versioned deployment snapshot in Azure Container Apps that supports gradual traffic changes and rollback.
AZ-204 is testing whether you can separate:
| Need | Strongest first lane | Why it fits |
|---|---|---|
| Publish and manage images centrally | Azure Container Registry | Registry is the image source-of-truth lane |
| Quick isolated container run with minimal platform expectations | Azure Container Instances | Straightforward container execution |
| Managed container app with scaling and revision-based rollout behavior | Azure Container Apps | App-shaped managed hosting |
| If the question says | Think first about |
|---|---|
| build, publish, reuse, pull image | Azure Container Registry |
| run one or a few containers without a broader app-hosting platform | Azure Container Instances |
| managed app platform, revisions, traffic changes, and scaling behavior | Azure Container Apps |
flowchart LR
A["Build container image"] --> B["Push to Azure Container Registry"]
B --> C{"How should it run?"}
C -->|Quick isolated container execution| D["Azure Container Instances"]
C -->|Managed app with revisions and scaling| E["Azure Container Apps"]
| Trap | Better reading |
|---|---|
| “ACR hosts the running application.” | ACR stores images. It is not the runtime. |
| “Any container workload should go to Container Apps.” | If the prompt is about a simple isolated run, ACI can be the stronger first answer. |
| “ACI and Container Apps are just naming variants.” | ACI is simpler execution; Container Apps is the more app-platform-oriented lane. |
| “Revisions are a registry feature.” | Revisions belong to Container Apps deployment behavior, not image storage. |
A team builds a container image in CI, wants a central image store, and then needs to run the workload as a managed application with revision-based rollout behavior rather than as a one-off container.
The strongest reading is:
Correct answer: 1. The problem splits into image storage and managed application hosting.
| Requirement | Strong lane |
|---|---|
| publish and manage images centrally | Azure Container Registry |
| simple one-off container run or quick isolated workload | Azure Container Instances |
| managed microservice-style app with scaling and revisions | Azure Container Apps |