PHP: what is pcntl_signal used for?

[Punkey]

I found a chunk of code that I haven't seen before:\[code\]declare(ticks = 1);pcntl_signal(SIGINT, array($this, "catchSignal"));pcntl_signal(SIGTERM, array($this, "catchSignal"));\[/code\]I looked up the function in the PHP documentation, but I still don't understand what this is used for. Please help me understand what this is used for and some examples of where this should be implemented.