PID
1. Short for product identification, PID is a unique number that helps identify a hardware product. For example, in the case of a computer mouse, its PID is often found on the bottom of the mouse or in the case of a wireless mouse inside the battery compartment.
2. Short for process identifier, a PID is a unique number that identifies each of the running processes in an operating system such as Linux, Unix, Mac OS X, and Microsoft Windows. In the below output, is an example of a few of the processes running in Windows and their associated PID's listed in the PID column.
| Image Name | PID | Session Name | Session # | Mem Usage |
| System Idle Process | 0 | Services | 0 | 24 K |
| System | 4 | Services | 0 | 154,040 K |
| smss.exe | 308 | Services | 0 | 1,424 K |
| avgchsva.exe | 400 | Services | 0 | 127,476 K |
Listing running PID's
- Microsoft Windows users can use the tasklist command from the command line to list all tasks and associated PID. Within Windows you can see each of the services PID by opening the Services tab in Task Manager.
- Unix and Linux users can list PIDs by using the ps command and the top command.
Stopping or killing a PID
- Microsoft Windows users can end a PID by using the taskkill command from the command line or through the Task Manager.
- Linux and Unix users can kill a PID using the kill command.