What is a container You may have encountered some of following issues when you compile or run a software: bash: command not found: <command> undefined reference to <function>. usr/bin/ld: cannot find -l<nameOfTheLibrary> FileNotFoundError: [Errno 2] No such file or directory etc. Containers are here to save you. With containers, you won’t need to worry about any environment issues. If the container is working on the developer’s side, it works on your side without any doubt.