For ex - if I enter ping one.com the process will keep running - if I want to stop that process, I can type Ctrl C which if I'm not mistaken, will kill the process completely. If instead, I stop it with Ctrl Z, isn't it true that the process can still be operating in the background at some level? How is one able to spot a condition where a process is running but can't be seen on the terminal screen? Thanks.
jobs built-in to see running tasks for your current shell.
$ ping google.com >/dev/null 2>&1 &  32406 $ jobs + Running ping google.com > /dev/null 2>&1 & $ ping google.com [...] ^Z + Stopped ping google.com $ jobs - Running ping google.com > /dev/null 2>&1 & + Stopped ping google.com
To kill all running jobs, you can leverage
jobs -p which lists the pids of all jobs.
$ for job in $(jobs -p); do kill $job; wait $job; done
Further reading: http://www.tldp.org/LDP/abs/html/x9644.html
ps -aux | grep "processname" to see if process running
kill "processID" to kill specified process, PID is second set of numbers in previous command in line with target process
killall "processname" to kill all processes with defined name