The words UP and DOWN indicate whether the command is still running, while the s and x keys can be used to start and stop processes.
If you’ve ever wanted to run multiple Linux shell commands at the same time, you’ve probably used either Tmux or GNU Screen. These tools, however, are usually used to run much more long-lived processes. If you have a bunch of commands that you run in parallel, regularly, look at Mprocs, which also displays the output of each command separately.