Can you list the types of signals used in Linux and explain their purposes?

In Linux, signals are a way of asynchronously notifying processes about events. Here are the main types of signals and their purposes:

• SIGINT (2) — interrupt the process (usually Ctrl+C in the terminal).
• SIGTERM (15) — request for the process to terminate gracefully.
• SIGKILL (9) — immediately terminate the process (cannot be caught or ignored).
• SIGSTOP (19) — suspend the process (cannot be caught).
• SIGCONT (18) — continue a suspended process.
• SIGHUP (1) — hangup signal, often used to reload configuration.
• SIGQUIT (3) — quit with a core dump.
• SIGALRM (14) — timer signal.
• SIGUSR1 and SIGUSR2 (10 and 12) — user-defined signals for arbitrary purposes.

Each signal has a number and a default action, but processes can catch most signals to perform special handlers.