Docker commands which take the name of a container accept three different forms:
docker ps to view these values for the containers on your system.
The UUID is generated by Docker and cannot be modified. You can provide a name to the container when you start it
docker run --name <given name> <image>. Docker will generate a random name to the container if you don't specify one at the time of starting the container.
NOTE: The value of the UUID (or a 'short' UUID) can be any length as long as the given value is unique to one container