The kill(1) command is used for either terminating a process or sending a less cruel signal to it. Keep in mind that the fact that you can send a signal to a process does not mean that the process can or has code to handle this signal.
By default, kill(1) sends the SIGTERM signal. If you want to find out all the supported signals of your Unix machine, you should execute the kill -l command. On a macOS Sierra machine, the output of kill -l is the following:
$ kill -l 1) SIGHUP 2) SIGINT 3) SIGQUIT 4) SIGILL 5) SIGTRAP 6) SIGABRT 7) SIGEMT 8) SIGFPE 9) SIGKILL 10) SIGBUS 11) SIGSEGV 12) SIGSYS 13) SIGPIPE 14) SIGALRM 15) SIGTERM 16) SIGURG 17) SIGSTOP 18) SIGTSTP 19) SIGCONT 20) SIGCHLD 21) SIGTTIN 22) SIGTTOU 23) SIGIO 24) SIGXCPU 25) SIGXFSZ 26) SIGVTALRM 27) SIGPROF 28) SIGWINCH 29) SIGINFO 30) SIGUSR1 ...