What are the differences between SIGKILL and SIGTERM signals in process management?

SIGTERM and SIGKILL are signals used for process management in Unix-like systems, but they have fundamental differences:

• SIGTERM (signal 15) is a request signal to terminate a process. The process can catch this signal, handle it (for example, save data, free resources), and terminate gracefully. If the process ignores SIGTERM, it will not be forcibly terminated.

• SIGKILL (signal 9) is a signal for immediate and forceful termination of a process. It cannot be caught, blocked, or ignored. The operating system immediately terminates the process without any cleanup.

Thus, SIGTERM is a "polite" request to terminate, while SIGKILL is a "hard" forced kill of the process.