What is Docker?

Docker is used to create and run containers. A container stores a website or application along with all the files, images, text, runtime (such as PHP, Python, or Node.js), libraries, dependencies, and configuration files required to run it properly. It makes it easy to move the application from one computer or server to another. If you want to run the application on another computer or a remote server, you only need to move the container. Since the container already contains everything the application needs, you do not need to install the files, libraries, dependencies, or runtime again.

Example:

Suppose you have a website running on a cloud server. For any reason, if you move a Docker container to a new private server, you do not need to install the website files, libraries, dependencies, runtime, or configuration files again because they are already included inside the Docker container.