The status of a process tells you whether it is currently doing something or not. There are four statuses that a process can have:
Processes that are currently doing something (for example, a web browser loading a web page). Running processes are those that are actively using the processor (CPU).
Processes that are not currently doing anything (for example, because they are waiting for something to happen). They don't use any of the processor's time, but still take up memory. If they need to do something, they will "wake up" and change their status to running.
A stopped process is one that has been put to sleep manually. You might want to stop a process temporarily if it is using too much processing time, for example.
To do this, click the process in the
A zombie process is one that has finished running and will never start again, but is being kept in the list of processes for some reason. This usually happens because it was started by another program that needs to know if it finished successfully or not, but which has not checked on the process yet.
Zombie processes do not use any memory or processing time, and will eventually go away. You do not need to do anything to get rid of them.
The majority of processes will either be running or sleeping.