In robotics, Docker can be an interesting tools. For example, it can be used to deal with various versions of ROS without changing the host OS. It can also be used to run old Python 2.7 codes without having to install Python 2.7 and required packages on the host OS.

Just to recall some basic definitions, the host and guest terminology will used. The host computer, or simple host, is the computer your are currently working on. The Docker container will be consider as a guest that will share some resources from the host (for ex, the Operation System or OS).