Editing Process control block (section)

{{For|printed circuit boards (PCB)|Printed circuit board}}

{{Short description|Data structure storing a computer process's information}}

A '''process control block''' ('''PCB'''), also sometimes called a '''process descriptor''', is a data structure used by a computer [[operating system]] to store all the information about a [[Process (computing) | process]].

When a process is created (initialized or installed), the operating system creates a corresponding process control block, which specifies and tracks the process state (i.e. new, ready, running, waiting or terminated). Since it is used to track process information, the PCB plays a key role in [[context switching]].<ref>{{cite web | url=https://www.baeldung.com/cs/process-control-block | title=Process Control Block &#124; Baeldung on Computer Science | date=25 June 2020 }}</ref>

An operating system kernel stores PCBs in a process table.<ref>{{Cite web |title=Class 9: The Unix Filesystem |url=https://www.usna.edu/Users/cs/wcbrown/courses/IC221/classes/L09/Class.html |access-date=2023-12-09 |website=www.usna.edu}}</ref>

The current [[working directory]] of a process is one of the properties that the kernel stores in the process's PCB.<ref>{{Cite web |title=CS 537 Notes: Directories |url=https://pages.cs.wisc.edu/~bart/537/lecturenotes/s25.html |access-date=2023-12-09 |website=pages.cs.wisc.edu}}</ref>