processIdentifier

A processIdentifier, commonly referred to as a process ID or PID, is a numeric identifier assigned by an operating system to a running process. It serves as a handle by which the system and applications can refer to that specific process for management, monitoring, and inter-process communication. In some API documentation, including certain programming frameworks, the term processIdentifier is used as a property or field that exposes the process’s PID.

Assignment and scope: When a process is created, the operating system allocates a new, unique identifier for its lifetime. The PID remains valid for the duration of the process and is used by the kernel to manage resources, schedule execution, and support signals or interrupts. After the process terminates, its PID may be reused for new processes, which means identifiers are not guaranteed to remain unique over time.

Usage: PIDs are widely used in system calls and tooling. In Unix-like systems, calls such as getpid() retrieve the current process’s identifier, while getppid() returns the parent’s PID. Commands like kill or waitpid operate using PIDs to signal processes or collect status information. In programming environments, APIs often expose a processIdentifier or similar property to reference child or managed processes; for example, a launched process in a runtime may provide its processIdentifier for later interaction or termination.

Cross-platform notes: The concept exists across operating systems, though representations differ. Unix-like systems typically use pid_t values; Windows uses a numeric process ID (often a DWORD). The exact lifetime, reuse policy, and accompanying metadata (such as parent process ID) vary by platform and kernel design.