What identification number is associated with each running process in Linux?

The identification number associated with each running process in Linux is the Process ID, commonly referred to as PID. Every process that is started in a Linux environment is assigned a unique PID, which allows the system to manage and track each process individually. This unique identifier is critical for operations such as monitoring process status, terminating a process, or modifying its behavior.

The PID is crucial because it helps differentiate between multiple processes that may be running at the same time. For instance, if a user wants to stop a particular application, they can use its PID in commands like kill to target the specific process without affecting others. By providing a unique identifier for each process, the system can efficiently manage resources and maintain stability.

Other identification numbers, such as UID (User ID) for user identification, GID (Group ID) for group identification, and SID (Session ID) for session tracking, serve different purposes and are not directly associated with running process management in the same way that PID is. Thus, the importance of PID lies in its role as the fundamental way to identify and manage processes in a Linux environment.