Summary

Docker provides a virtualization platform which uses container infrastructure, lighter than hypervisor one.
Docker runs on not only Linux but also Windows and macOS today.

This post shows how to install Docker on Debian 10 Buster.

Reference

• The official documentation by Docker

A digression

First of all, remember not to do:

$ sudo apt install docker

It is unrelated to Docker platforms.
It enables you to use wmdocker which is "System tray for KDE3/GNOME2 docklet applications".

Tutorial

Install requirements.

$ sudo apt update
$ sudo apt install apt-transport-https ca-certificates curl gnupg2 software-properties-common 

Get the official GPG key.

$ curl -fsSL https://download.docker.com/linux/debian/gpg | sudo apt-key add -

In order to add the repository, create file:

$ sudo nvim /etc/apt/sources.list.d/docker-ce.list

and write in it:

deb [arch=amd64] https://download.docker.com/linux/debian buster stable

Update apt package index and install Docker.

$ sudo apt update
$ sudo apt install docker-ce

Thas's it :)