Process Control Block

• Process Control Block

The OS must know specific information about processes in order to manage, control them and also to implement the process model, the OS maintains a table (an array of structures), called the process table, with one entry per process.
These entries are called process control blocks (PCB) - also called a task control block
http://siber.cankaya.edu.tr/ozdogan/OperatingSystems/ceng328/node87.html

• Process Control Block

A process in an operating system is represented by a data structure known as a process control block (PCB) or process descriptor. The PCB contains important information about the specific process including

The current state of the process i.e., whether it is ready, running, waiting, or whatever.
Unique identification of the process in order to track "which is which" information.
A pointer to parent process.
Similarly, a pointer to child process (if it exists).
The priority of process (a part of CPU scheduling information).
Pointers to locate memory of processes.
A register save area.
The processor it is running on.

The PCB is a certain store that allows the operating systems to locate key information about a process. Thus, the PCB is the data structure that defines a process to the operating systems.
http://www.personal.kent.edu/~rmuhamma/OpSystems/Myos/processControl.htm