There are several different signals, each with its own meaning. The set of signals and their names is defined by the operating system. Each signal has a standard effect on the subprocess.
Most signals kill the subprocess, but some stop or resume execution instead.
You can send signals explicitly by calling the functions in this section. The argument process-name must be either a process, the name of one, or nil . If it is nil , the process defaults to the process associated with the current buffer. An error is signaled if process-name does not identify a process. If the process is a job-control shell, this means the shell's current subjob.