Docker Basics MCQs with Answers and Explanations

docker build reads the instructions in a Dockerfile and creates a Docker image layer by layer. The resulting image can then be run as a container or pushed to a registry.

Docker Compose is a tool for defining and running multi-container Docker applications using a docker-compose.yml file. It simplifies orchestration of multiple interdependent services in development environments.

The docker ps command lists all currently running containers. Adding the -a flag shows all containers including stopped ones.

A Docker container image is a read-only template containing the application code, runtime, libraries, and dependencies. Running an image creates a container instance.

docker-compose up reads the docker-compose.yml file, builds images if needed, and starts all defined services as containers. It simplifies managing multi-container applications.

A Dockerfile is a text file containing instructions to build a Docker image. It defines the base image, dependencies, configuration, and commands needed to run an application in a container.

Docker containers help package applications and dependencies consistently, making them portable across environments.

A Docker image is a read-only template used to create containers.

Containers are lightweight and share the host OS kernel, making them more efficient than full virtual machines in many cases.