Executing the command ps returns a list of processes being run by the user account that invokes the command. This list includes the process id, the command that started the process, and the terminal type and number. Any process in the list may be terminated using the kill command with the associated process id obtained from the list generated by ps.
To see a list of all processes use the ps -a command. Unless done by the root account, only the listed processes which the user started may be killed by that user. The root account can kill any process on the system with kill -9 <process id>.
While the ps command includes a field for the status of the process, the only process in a R(un) status is the process ps itself. All other processes are marked S(uspended). Another tool is required to get a real-time picture of what these processes are doing.