PID

1. Short for product identification or product id, PID is a unique number that helps identify a hardware product or a registered software 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. When talking about software a product id is more often referred to as a CD-KEY or Product key and is a unique number that allows the user to register their software. See our product key page for further information on this term.

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

Also see: Fork, Process