Docker

Containers, Images, and Registries

Connect a running container with its packaged image, registry location, repository name, and immutable digest before choosing what to run.

Beginner13 min read
Docker lessonContainer and orchestration foundationsPractice

UNTIMED COACHING

Practice before the pressure

Use feedback to correct the model, not merely memorize an option position.

GUIDED PRACTICE

Practice the lesson questions

Answer normal lesson questions without a timer. Every answer includes an explanation, and incorrect answers can be tried again before continuing.

CONCEPT MODELS

See the lesson as a system

Use these visual guides to connect the key ideas before answering the questions.

Follow an image into a running containerSeparate the packaged image, registry service, repository mapping, and resulting container process.
Follow an image into a running containerA flow connects an image package with its registry, repository, and resulting container process.
Image packagePackage supplies read-only application layers
Registry serviceService stores and distributes images
Repository mappingMapping groups related image versions
Container processProcess runs isolated application files
Verify the exact image before runtimeUse an immutable digest, a local inspection, an exact match, and a boundary against moving tags.
Verify the exact image before runtimeA verification model connects an image digest with its inspection, expected match, and tag safety boundary.
Artifact dataData pins exact image content
Starting checkInspect pulled image identifier
Expected resultLocal digest matches approved content
Safety boundaryReject moving tag as identity proof