1. kill command can be used to send TERM signal.
2. SIGTERM 15 Term Termination signal
Signal is an user space interrupt.
Sending a Signal
The following system calls and library functions allow the caller to send a signal:
raise(3) Sends a signal to the calling thread.
kill(2) Sends a signal to a specified process, to all members of a
specified process group, or to all processes on the system.
killpg(2) Sends a signal to all of the members of a specified process
group.
pthread_kill(3) Sends a signal to a specified POSIX thread in the same process
as the caller.
tgkill(2) Sends a signal to a specified thread within a specific
process. (This is the system call used to implement pthread_kill(3).)
sigqueue(2) Sends a real-time signal with accompanying data to a specified
process.
http://www.kernel.org/doc/man-pages/online/pages/man7/signal.7.html
Beautiful Work 