Obviously, the more processes running on a particular machine, the harder it may be for that machine to handle all processes in an efficient and timely manner. There are commands to help you identify your processes that are currently running. One of these is the ps command and the other is an interactive one called top . These may lock up your system where you can't do anything or just simply lock up one application. In cases where this happens it is important to understand what processes are and some governing factors regarding processes.
All processes have parent processes.
For example, a shell is required to start a program or application. Sometimes a process can be so confused that only by killing its parent process can it be eliminated. Let's look at the ps command and how it displays the results. Also let's look at some of the more popular options that ps allows. By typing ps -a at the command prompt that will give you a list of processes running on that terminal.