A process is a running instance of a program. Understanding the distinction between a program and a process, and the resources a process uses, is essential for understanding how an operating system runs applications safely and reliably.
A program is a passive collection of instructions, typically stored in a file. A process is an instance of that program executing after its instructions have been loaded into memory. The program is like a recipe; the process is the act of following that recipe, with its own working materials and current progress.
All flashcards
What is a process?
A process is an instance of a computer program being executed. It includes execution activity and the associated context and resources needed for the operating system to manage it.
How does a process differ from a program?
A program is a passive collection of instructions, usually stored in a file. A process is an executing instance of those instructions after they have been loaded into memory.
What information may a process's memory contain?
It may contain executable code, process-specific data, a call stack for active subroutines and events, and a heap for data created during execution.
What is a process control block?
A process control block (PCB) is an operating-system data structure that holds information used to track and manage an active process.
What is inter-process communication?
Inter-process communication (IPC) uses controlled mechanisms that let processes exchange information or coordinate, such as passing one process's output to another.
Quiz questions
What is the key difference between a program and a process?Answer: A program is stored instructions, while a process is an executing instance of those instructions.
What is the primary purpose of a process control block (PCB)?Answer: It stores information the operating system uses to track and manage a process.
Which information is an example of processor state associated with a process?Answer: The contents of processor registers and memory-addressing information.
Can two processes be associated with the same program?Answer: Yes; each can have its own execution activity and process-specific state.
Why do operating systems provide controlled inter-process communication (IPC)?Answer: It lets processes exchange information while helping maintain isolation, security, and reliability.