The article did a pretty good job of explaining the differences. Did you just skim it quickly? Mainly, no need for a daemon or running as root.

It's not him. Docker was retired last year in case you are not aware of that.

RedHat replaced docker with their own software. The command is still "docker" but it doesn't run docker. Since RedHat basically runs Linux, docker is dead, it will be transparently killed from all the Linux distributions soon.