Operating System-differences between processes, programs, and jobs

Differences between programs and processes:

(1) The process can describe concurrency more realistically, but the program cannot.

(2) A process is composed of two parts: a program and data. A process is the basic unit for competing with the limited resources of a computer system and scheduling of a process processor.

(3) A program is a static concept; a process is a process of executing a program on a processing machine and a dynamic concept.

(4) A process has a life cycle and has its birth and death. Is short, and the program is relatively long.

(5) One program can be used as the running program of multiple processes. One process can also run multiple programs.

(6) The process has the function of creating other processes, but the program does not.

 

Differences between jobs and processes:

A process is the execution process of a program on a dataset and the basic unit for resource allocation. A job is a task that a user needs to complete on a computer. It is a set of jobs that require the computer to do. The completion of a job involves four stages: Job submission, job reception, job execution, and job completion. A process is a description of the execution process of a submitted program and the basic unit of resource allocation. The main differences are as follows.

(1) A job is the task entity that the user submits tasks to the computer. After a user submits a job to a computer, the system puts the job into the external store and waits for execution in the queue. Processes are the execution entity for completing user tasks and the basic unit for applying to the system for resource allocation. Any process, as long as it is created, always has a corresponding part in the memory.

(2) A job may consist of multiple processes and must be composed of at least one process. In turn, it cannot be true.

(3) The concept of a job is mainly used in a batch processing system, and there is no concept of a job in a time-based system such as UNIX. The concept of process is used in almost all multi-channel program systems.

 

Links between jobs, processes, and programs:

A job usually consists of three parts: Program, data, and Operation Manual. Each process is composed of PCB, program, and data set. This indicates that the program is a part of the process and the entity of the process. Therefore, a job can be divided into several processes to complete, and each process has its own body-programs and data sets.

Operating System-differences between processes, programs, and jobs