What's the "PID" means in SM21

Dear All

After running SM21, SAP shows the messages as

Stop Workproc 5, PID 12978;

and Stop Workproc 1, PID 25698.

What does the “PID” means?

There’s another question about the message as

"Run-time error ""MESSAGE_TYPE_X"" occurred

Short dump ""130312 182717 fedsap1_ PRD_01 "" generated"

What does “130312 182717” mean?

Is it the server name?

1. Regards.