To see all the current processes you need to use the ps command. ps displays information about a selection of the active processes.
to see all the processes:
it will display it's PID (it's process id), TTY (with console has started this process), TIME (cumulative CPU time) and CMD (the command). for all the information about it:
to search for a specific process and a detailed view:
ps aux | grep transmission
where transmission is the process we are searching for. the second column will display the PID for our process.
to kill it (send a signal to a process):
sudo kill -9 8785
where 8785 is the PID we searched for.
for more information about kill command: