What is a Docker Container?

When we develop an Application and move it between various environments QA, Staging, Production etc, we need to take care of various environmental factors like Operating System version, security patches, network configuration etc. When there is any deviation in these settings the application starts behaving differently and becomes difficult to identify the cause.

Containers help us make this easier, Containers are an abstraction at the app layer that packages code and dependencies together. A Container packages up code and all its dependencies so the application runs quickly and reliably from one computing environment to another.

Multiple containers can run on the same machine and share the OS kernel with other containers, each running as isolated processes in userspace. Containers take up less space than VMs.