Docker MCQs and Answers with Explanation: Docker is a widely used platform for building, packaging, and deploying applications as containerized software. It enables developers to create a standardized environment for their applications, making it easier to move them between different computing environments. To better understand Docker and its various features, it is important to have a solid understanding of the concepts and terminology associated with it. And this can be achieved through these Top 65 Docker MCQ Questions with Answers that we have established below. This Docker Online Quiz will not only help the freshers to gain knowledge about this concept but also enables the experienced individuals to enhance their knowledge regarding Docker .
Docker MCQs with Answers
We assure the aspirant’s Docker MCQ Questions that we have enclosed here can be very helpful. In this article, we will explore some of the most commonly asked Docker Multiple Choice Questions, covering topics such as containers, images, networks, and more. By the end of this article, you should have a better understanding of Docker and its key features.
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Docker Multiple Choice Questions
| Name | Docker |
| Exam Type | MCQ (Multiple Choice Questions) |
| Category | Technical Quiz |
| Mode of Quiz | Online |
Top 65 Docker MCQ Questions with Answers | Docker Quiz
1. What is Docker?
A) A containerization platform
B) A virtual machine platform
C) A cloud computing platform
D) A programming language
Answer: A
Explanation: Docker is a containerization platform that allows developers to package applications and their dependencies into containers that can be easily deployed and run on any system that supports Docker.
2. What is the primary advantage of using Docker?
A) Improved application security
B) Improved application performance
C) Improved application portability
D) Improved application scalability
Answer: C
Explanation: Docker enables developers to package applications and their dependencies into containers that can be easily moved between different systems, making it easy to deploy and run applications in different environments.
3. What is a Docker image?
A) A running container
B) A snapshot of a container
C) A blueprint for a container
D) A configuration file for a container
Answer: B
Explanation: A Docker image is a snapshot of a container that contains all the files, dependencies, and configurations needed to run the application inside the container.
4. What is a Docker container?
A) A running instance of a Docker image
B) A snapshot of a Docker image
C) A blueprint for a Docker image
D) A configuration file for a Docker image
Answer: A
Explanation: A Docker container is a running instance of a Docker image that contains the application and its dependencies.
5. How does Docker differ from traditional virtualization?
A) Docker uses hardware-level virtualization
B) Docker uses software-level virtualization
C) Docker provides full isolation of the underlying system
D) Docker provides less isolation of the underlying system
Answer: B
Explanation: Docker uses software-level virtualization, which means that containers share the same underlying kernel as the host system, but have their own isolated file system and network stack. This provides a lightweight and efficient way to package and run applications.
6. What is a Dockerfile?
A) A configuration file for a Docker container
B) A configuration file for a Docker image
C) A configuration file for a Docker network
D) A configuration file for a Docker volume
Answer: B
Explanation: A Dockerfile is a configuration file that specifies how to build a Docker image. It includes instructions for installing dependencies, copying files, and configuring the container.
7. What is the purpose of a Docker registry?
A) To store Docker images
B) To store Docker containers
C) To manage Docker networks
D) To manage Docker volumes
Answer: A
Explanation: A Docker registry is a centralized location for storing and sharing Docker images. It allows developers to easily distribute their applications to other users and systems.
8. What is Docker Compose?
A) A tool for managing multiple Docker containers
B) A tool for managing Docker images
C) A tool for managing Docker networks
D) A tool for managing Docker volumes
Answer: A
Explanation: Docker Compose is a tool for defining and managing multi-container Docker applications. It allows developers to define a set of related containers, their configuration, and their dependencies in a single file.
9. What is the difference between a Docker container and a Docker service?
A) A container is a running instance of an image, while a service is a set of containers that perform a specific task.
B) A container is a virtualized environment for running an application, while a service is a tool for managing Docker images.
C) A container is a lightweight and efficient way to package and run an application, while a service is a more complex tool for deploying and managing applications.
D) A container and a service are the same thing.
Answer: A
Explanation: A Docker container is a running instance of an image, while a Docker service is a set of containers that perform a specific task. Services are used to scale and distribute applications across multiple nodes in a Docker swarm.
10. What is a Docker swarm?
A) A cluster of Docker nodes
B) A single Docker node
C) A Docker container
D) A Docker image
Answer: A
Explanation: A Docker swarm is a cluster of Docker nodes that work together to run Docker services and distribute application workloads across multiple nodes.
11. What is the purpose of a Docker stack?
A) To define and manage multi-service applications in a Docker swarm
B) To define and manage single-service applications in a Docker swarm
C) To define and manage Docker images in a Docker registry
D) To define and manage Docker containers on a single node
Answer: A
Explanation: A Docker stack is used to define and manage multi-service applications in a Docker swarm. It allows developers to define a set of related services, their configuration, and their dependencies in a single file.
12. What is the difference between a Docker container and a virtual machine?
A) A Docker container shares the host operating system kernel, while a virtual machine has its own kernel.
B) A Docker container is smaller and faster than a virtual machine.
C) A Docker container uses less resources than a virtual machine.
D) All of the above.
Answer: D
Explanation: Docker containers share the host operating system kernel, which makes them smaller, faster, and more efficient than virtual machines. They also use less resources and provide better performance.
13. What is the purpose of a Docker volume?
A) To store persistent data outside of the container file system
B) To store temporary data inside the container file system
C) To manage network traffic between containers
D) To manage container configuration and settings
Answer: A
Explanation: A Docker volume is used to store persistent data outside of the container file system. It allows developers to separate data storage from the application code, and makes it easy to backup, restore, and migrate data between containers.
14. What is the difference between a Docker volume and a Docker bind mount?
A) A Docker volume is managed by Docker, while a bind mount is managed by the host operating system.
B) A Docker volume is more secure than a bind mount.
C) A Docker volume is faster than a bind mount.
D) A Docker volume is used for temporary data, while a bind mount is used for persistent data)
Answer: A
Explanation: A Docker volume is managed by Docker, which means that it can be easily backed up, restored, and migrated between containers. A bind mount is managed by the host operating system, which means that it is less secure and less portable than a Docker volume.
15. What is a Docker network?
A) A virtual network that connects Docker containers
B) A physical network that connects Docker nodes
C) A way to manage Docker images
D) A way to manage Docker containers
Answer: A
Explanation: A Docker network is a virtual network that connects Docker containers and allows them to communicate with each other. It provides a way to isolate containers and control network traffic between them.
16. What is the difference between a Docker network and a host network?
A) A Docker network provides better isolation and security than a host network.
B) A Docker network is managed by Docker, while a host network is managed by the host operating system.
C) A Docker network is faster than a host network.
D) A Docker network uses less resources than a host network.
Answer: B
Explanation: A Docker network is managed by Docker, which means that it can be easily configured, monitored, and managed using Docker tools. A host network is managed by the host operating system, which means that it is less flexible and more difficult to manage.
17. What is the default Docker registry?
A) Docker Hub
B) Docker Store
C) Docker Cloud
D) Docker Repository
Answer: A
Explanation: Docker Hub is the default Docker registry. It provides a large collection of official and community images, and can be accessed from anywhere with an internet connection.
18. What is the purpose of a Dockerfile?
A) To define a Docker image
B) To define a Docker container
C) To manage Docker volumes
D) To manage Docker networks
Answer: A
Explanation: A Dockerfile is used to define a Docker image. It provides a set of instructions for building the image, such as what base image to use, what packages to install, and what files to copy into the image.
19. What is the difference between a Docker image and a Docker container?
A) A Docker image is a blueprint for a container, while a container is a running instance of an image.
B) A Docker image is smaller than a container.
C) A Docker image is faster than a container.
D) A Docker image is used for temporary data, while a container is used for persistent data)
Answer: A
Explanation: A Docker image is a blueprint for a container, which means that it provides all the instructions and files needed to create a running instance of the image. A container is a running instance of an image, which means that it has its own file system, network, and process space.
20. What is the purpose of the ENTRYPOINT instruction in a Dockerfile?
A) To specify the command that should be run when a container is started
B) To specify the base image for the Dockerfile
C) To specify the user that should run the container
D) To specify the working directory for the container
Answer: A
Explanation: The ENTRYPOINT instruction in a Dockerfile is used to specify the command that should be run when a container is starteD) It is often used to define the primary process for the container, such as a web server or database server.
21. What is the purpose of the CMD instruction in a Dockerfile?
A) To provide default arguments for the ENTRYPOINT command
B) To specify the base image for the Dockerfile
C) To specify the user that should run the container
D) To specify the working directory for the container
Answer: A
Explanation: The CMD instruction in a Dockerfile is used to provide default arguments for the ENTRYPOINT commanD) It is often used to specify additional options or parameters for the primary process defined by the ENTRYPOINT instruction.
22. What is the purpose of the EXPOSE instruction in a Dockerfile?
A) To specify the port that a container should listen on
B) To specify the base image for the Dockerfile
C) To specify the user that should run the container
D) To specify the working directory for the container
Answer: A
Explanation: The EXPOSE instruction in a Dockerfile is used to specify the port that a container should listen on. It does not actually publish the port, but instead informs Docker that the container will listen on that port when it is running.
23. What is the purpose of the VOLUME instruction in a Dockerfile?
A) To create a mount point for a host directory to be mounted as a data volume
B) To specify the base image for the Dockerfile
C) To specify the user that should run the container
D) To specify the working directory for the container
Answer: A
Explanation: The VOLUME instruction in a Dockerfile is used to create a mount point for a host directory to be mounted as a data volume in the container. This allows data to be persisted between container runs and makes it easier to manage data)
24. What is the purpose of Docker Swarm?
A) To manage a cluster of Docker nodes as a single virtual system
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker Swarm is a tool for managing a cluster of Docker nodes as a single virtual system. It provides a simple and easy way to orchestrate Docker containers across multiple hosts and supports features like load balancing and service discovery.
25. What is the purpose of the Docker stack?
A) To deploy a group of services defined in a Compose file to a Swarm cluster
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker stack is a tool for deploying a group of services defined in a Compose file to a Swarm cluster. It provides a simple and easy way to manage a set of related services as a single unit, and allows for scaling and updates of the services.
26. What is the purpose of the Docker Machine?
A) To create Docker hosts on local or remote machines
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker Machine is a tool for creating Docker hosts on local or remote machines. It provides a simple and easy way to set up a Docker environment on any machine and supports a variety of virtualization platforms and cloud providers.
27. What is the purpose of Docker Hub?
A) To store and distribute Docker images
B) To manage Docker containers
C) To manage Docker networks
D) To manage Docker volumes
Answer: A
Explanation: Docker Hub is a cloud-based registry service that allows developers to store and distribute Docker images. It provides a large collection of official and community images, and can be accessed from anywhere with an internet connection.
28. What is the purpose of Docker Desktop?
A) To provide an easy-to-install Docker environment for Windows and Mac OS
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker Desktop is a tool for providing an easy-to-install Docker environment for Windows and Mac OS. It includes a variety of tools and services, such as a Docker CLI, Compose, and Kubernetes support.
29. What is the purpose of Docker Compose?
A) To define and run multi-container Docker applications
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker Compose is a tool for defining and running multi-container Docker applications. It allows developers to define a set of related services in a single YAML file, and then start and stop the entire application with a single commanD)
30. What is the purpose of Docker logs?
A) To view the logs of a Docker container
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker logs is a command for viewing the logs of a Docker container. It allows developers to view the standard output and error logs of a container, which can be useful for debugging and troubleshooting.
31. What is the purpose of Docker exec?
A) To run a command inside a running Docker container
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker exec is a command for running a command inside a running Docker container. It allows developers to execute arbitrary commands inside a container, which can be useful for debugging, troubleshooting, and managing a container.
32. What is the purpose of Docker stats?
A) To view the resource usage of a Docker container
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker stats is a command for viewing the resource usage of a Docker container, including CPU usage, memory usage, and network activity. It can be useful for monitoring the performance of a container and identifying potential performance bottlenecks.
33. What is the purpose of the Docker network?
A) To create and manage Docker networks
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker volumes
Answer: A
Explanation: Docker network is a command for creating and managing Docker networks. It allows developers to create custom networks for their containers, which can be used for communication between containers or isolation from other networks.
34. What is the purpose of Docker inspect?
A) To view detailed information about a Docker object
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker inspect is a command for viewing detailed information about a Docker object, such as a container, image, or network. It provides a JSON representation of the object’s configuration, which can be useful for troubleshooting and debugging.
35. What is the purpose of Docker image history?
A) To view the history of a Docker image
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker image history is a command for viewing the history of a Docker image, including the commands that were run to create the image and the layers that were added It can be useful for understanding how an image was created and identifying potential security vulnerabilities.
36. What is the purpose of Docker image prune?
A) To remove unused images from the local Docker host
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker image prune is a command for removing unused images from the local Docker host. It can be useful for freeing up disk space and reducing clutter on the host.
37. What is the purpose of Docker container prune?
A) To remove stopped containers from the local Docker host
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker container prune is a command for removing stopped containers from the local Docker host. It can be useful for freeing up resources on the host and reducing clutter.
38. What is the purpose of Docker volume?
A) To create and manage Docker volumes
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker volume is a command for creating and managing Docker volumes, which are used for persistent data storage between containers. Volumes can be used to share data between containers or to store data that needs to persist even when a container is stopped or removed
39. What is the purpose of Docker network create?
A) To create a custom Docker network
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker network create is a command for creating a custom Docker network. It allows developers to define a custom network with a specific name, IP range, and other settings.
40. What is the purpose of Docker network connect?
A) To connect a container to a Docker network
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker network connect is a command for connecting a container to a Docker network. It allows developers to specify which network a container should be connected to and assign it a unique IP address on that network.
41. What is the purpose of Docker network inspect?
A) To view detailed information about a Docker network
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker network inspect is a command for viewing detailed information about a Docker network, including the IP addresses and containers connected to the network. It can be useful for troubleshooting and debugging network connectivity issues.
42. What is the purpose of Docker network disconnect?
A) To disconnect a container from a Docker network
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker network disconnect is a command for disconnecting a container from a Docker network. It allows developers to remove a container from a network and free up network resources.
43. What is the purpose of Docker-compose up?
A) To start a multi-container Docker application defined in a Docker Compose file
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker-compose up is a command for starting a multi-container Docker application defined in a Docker Compose file. It automatically starts all the services defined in the Compose file and creates any necessary networks and volumes.
44. What is the purpose of Docker-compose down?
A) To stop and remove a multi-container Docker application defined in a Docker Compose file
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker-compose down is a command for stopping and removing a multi-container Docker application defined in a Docker Compose file. It stops all the services defined in the Compose file and removes any networks and volumes created by the Compose file.
45. What is the purpose of Docker-compose ps?
A) To view the status of containers in a multi-container Docker application defined in a Docker Compose file
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker-compose ps is a command for viewing the status of containers in a multi-container Docker application defined in a Docker Compose file. It shows which containers are running, stopped, or exited, and provides information about their status
46. What is the purpose of Docker-compose logs?
A) To view the logs of containers in a multi-container Docker application defined in a Docker Compose file
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker-compose logs is a command for viewing the logs of containers in a multi-container Docker application defined in a Docker Compose file. It allows developers to view the output of all containers in the Compose file or specify a single container to view.
47. What is the purpose of Docker-compose exec?
A) To execute a command in a running container in a multi-container Docker application defined in a Docker Compose file
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker-compose exec is a command for executing a command in a running container in a multi-container Docker application defined in a Docker Compose file. It allows developers to execute commands in a container’s environment without having to start a new container.
48. What is the purpose of Docker-compose build?
A) To build Docker images for services defined in a Docker Compose file
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker-compose build is a command for building Docker images for services defined in a Docker Compose file. It allows developers to build images for all the services in the Compose file or for a single service.
49. What is the purpose of Docker service create?
A) To create a Docker service to be deployed to a swarm
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker service create is a command for creating a Docker service to be deployed to a swarm. It allows developers to specify the image to use, the number of replicas to create, and other settings.
50. What is the purpose of the Docker service update?
A) To update a Docker service running in a swarm
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: A docker service update is a command for updating a Docker service running in a swarm. It allows developers to change the number of replicas, update the image, or modify other settings for the service.
51. What is the purpose of Docker service logs?
A) To view the logs of a Docker service running in a swarm
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker service logs is a command for viewing the logs of a Docker service running in a swarm. It allows developers to view the output of all replicas or specify a single replica to view.
52. What is the purpose of Docker service inspect?
A) To inspect a Docker service running in a swarm
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker service inspect is a command for inspecting a Docker service running in a swarm. It allows developers to view the details of the service, including its configuration, tasks, and replicas.
53. What is the purpose of Docker service ps?
A) To view the tasks of a Docker service running in a swarm
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker service ps is a command for viewing the tasks of a Docker service running in a swarm. It allows developers to view the status of each replica, including whether it is running, stopped, or failed
54. What is the purpose of Docker service rm?
A) To remove a Docker service running in a swarm
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker service rm is a command for removing a Docker service running in a swarm. It allows developers to stop all the replicas of the service and remove them from the swarm.
55. What is the purpose of Docker service rollback?
A) To roll back to a previous version of a Docker service running in a swarm
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker service rollback is a command for rolling back to a previous version of a Docker service running in a swarm. It allows developers to undo changes made to the service’s configuration or image.
56. What is the purpose of Docker service create –name?
A) To specify a name for a Docker service to be deployed to a swarm
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker service create -name is a command for specifying a name for a Docker service to be deployed to a swarm. The name can be used to refer to the service in other commands and in network communication.
57. What is the purpose of Docker stack deploy?
A) To deploy a Docker stack to a swarm
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker stack deploy is a command for deploying a Docker stack to a swarm. It allows developers to specify the Docker Compose file to use and deploy all the services in the file as a single unit across a cluster of nodes.
58. What is the purpose of Docker stack ps?
A) To view the tasks of a Docker stack running in a swarm
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker stack ps is a command for viewing the tasks of a Docker stack running in a swarm. It allows developers to view the status of each service in the stack, including whether it is running, stopped, or failed
59. What is the purpose of Docker stack rm?
A) To remove a Docker stack running in a swarm
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker stack rm is a command for removing a Docker stack running in a swarm. It allows developers to stop all the services in the stack and remove them from the swarm.
60. What is the purpose of Docker swarm init?
A) To initialize a new Docker swarm
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker swarm init is a command for initializing a new Docker swarm. It creates the first manager node of the swarm and generates a join token that can be used to add worker nodes.
61. What is the purpose of Docker swarm join?
A) To add a worker node to a Docker swarm
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker swarm join is a command for adding a worker node to a Docker swarm. It requires the join token generated by the manager node and can be used to join a node to the swarm from a remote host.
62. What is the purpose of Docker swarm leave?
A) To remove a node from a Docker swarm
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker swarm leave is a command for removing a node from a Docker swarm. It can be used to gracefully shut down a node and remove it from the swarm.
63. What is the purpose of Docker swarm update?
A) To update the configuration of a Docker swarm
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker swarm update is a command for updating the configuration of a Docker swarm. It allows developers to change the swarm’s settings, such as the network overlay driver, security options, and node availability.
64. What is the purpose of Docker swarm deploy?
A) To deploy a Docker service or stack to a swarm
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: Docker swarm deploy is a command for deploying a Docker service or stack to a swarm. It allows developers to specify the service or stack configuration and deploy it across the swarm.
65. What is the purpose of Docker swarm visualizer?
A) To visualize the nodes and services in a Docker swarm
B) To manage Docker images
C) To manage Docker containers
D) To manage Docker networks
Answer: A
Explanation: A docker swarm visualizer is a tool for visualizing the nodes and services in a Docker swarm. It provides a web-based interface for viewing the swarm’s topology, including the nodes and services running on each node.
In conclusion, Docker is a widely used containerization platform that allows developers to create, deploy, and manage applications in a more efficient and scalable way. By answering the Docker MCQs above, readers can gain a deeper understanding of Docker concepts and how to use them in their projects. With the continued growth and adoption of containerization technology, it is clear that Docker will remain an essential tool for modern software development. Please keep following the Freshersnow portal to equip yourself with more such useful articles.