Docker is a tool that enables you to create, deploy, and run applications by using containers. Containers allow you to package up an application with all of the parts it needs, such as libraries and other dependencies, and ship it all out as one package. By doing this, you can control exactly what your application runs on, regardless of the environment.
Docker is powerful because it gives you complete control over your environment while also being very portable. For example, if you wanted to move your dockerized application from your laptop to a server, all you would need to do is send the container file over. The same goes for sharing your application with others; simply send them the container and they can run it on their own machine without any issues.
Best of all, using Docker doesn’t require you to learn new technologies or rewrite your application. If your application runs on Linux, then it will run in a container with no changes required. That’s because containers are just isolated environments that use the same kernel as the host operating system.