Top 30 Docker Interview Questions and Answers Docker has become a common part of modern application development, deployment, and DevOps workflows. Docker interviews can cover everything from images, containers, Dockerfiles, networking, volumes, and registries to Docker Compose, security, troubleshooting, and Kubernetes. After completing my Docker Course from igmGuru, I started preparing with Docker interview questions that helped me understand the concepts commonly discussed in technical interviews. I am listing the same type of practical questions and answers in this article so that other learners and job seekers can use them for interview preparation.
1. What is Docker? Docker is a container platform used to package applications and their dependencies into portable containers. Containers provide isolated processes that share the host operating system kernel while keeping application environments separated.
2. What is a Docker container? A Docker container is a running instance of a Docker image. It contains the application, required libraries, configuration, and dependencies needed to run the application in an isolated process environment.
3. What is a Docker image? A Docker image is a read-only package containing the filesystem, application code, dependencies, and configuration needed to create a container. Images are commonly built from Dockerfiles and stored in registries.
4. What is the difference between a Docker image and a container? An image is the packaged template used to create containers. A container is a running or stopped instance created from an image. For example: docker run nginx