[kstenerud]

Yup, just like with people, name clashes in computers won't cause problems!

    # apt install docker
    Reading package lists... Done
    Building dependency tree       
    Reading state information... Done
    The following NEW packages will be installed:
      docker
    0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
    Need to get 12.9 kB of archives.
    After this operation, 45.1 kB of additional disk space will be used.
    Get:1 http://archive.ubuntu.com/ubuntu bionic/universe amd64 docker amd64 1.5-1build1 [12.9 kB]
    Fetched 12.9 kB in 1s (24.9 kB/s)
    Selecting previously unselected package docker.
    (Reading database ... 13860 files and directories currently installed.)
    Preparing to unpack .../docker_1.5-1build1_amd64.deb ...
    Unpacking docker (1.5-1build1) ...
    Setting up docker (1.5-1build1) ...
    root@testing:~# docker
    bash: docker: command not found

[jwilk]

For people who don't understand what happened here:

In Debian ecosystem, "docker" is a system tray application: https://icculus.org/openbox/2/docker/

Docker, the container software, is packaged as "docker.io".