1. Process identifier, also known as process ID or PID, is a unique number to identify each process running in an operating system such as Linux, Windows, and Unix. PIDs are reused over time and can only identify a process during the lifetime of the process, so it does not identify processes that are no longer running. This number can be used as a framework for various function calls, meaning processes can be manipulated and adjusted.
Listing PIDs
- Windows users can use the tasklist command from the command line to list all tasks and associated PIDs. They can see each of the services PID by opening the Services tab in Task Manager.
- For Unix and Linux users, PIDs are listed by using the ps command and the top command.
Killing a PID
- If a Windows user wants to kill a PID, it can be ended by using the taskkill command from the command line or through the Task Manager
- For Linux and Unix users, a PID is killed by using the kill command.
2. A packet identifier, also known as PID, is a 13-bit code used to identify each of the different video and audio content streams contained in an MPEG transport stream. A demultiplexer, a device used to take a single input line and route it to one of several digital output lines, extracts elementary streams from the transport stream in part by looking for packets identified by the same PID. In short, PID is used to synchronize video and audio packets.
