Program and Process: Differentiating the Active and Passive Entities of a System

 

The early computer systems only allowed one program to run at a time. However, current-day systems offer a feature to allow multiple programs to be run simultaneously and load into memory concurrently. The concept of the process was raised by multiple programming that requires former control. A process is a unit of work in a modern time-sharing system.

Therefore, a program that is under execution is known as a process. The process needs computer resources in order to accomplish its task. There can be a possibility that there may exist more than one process in a system that can require the same resource simultaneously. Therefore it’s the responsibility of the operating system that it has to manage all the processes and the needed resources in a more convenient and efficient way.

Some resources might need to be executed by one process at a single time so that the consistency could be maintained. Otherwise, the system may become vulnerable and the deadlock may occur.

What Is a Process?

A process is explained as the execution of a program. It is considered as an active entity and it realizes the actions specified in a particular program. A process needs some resources like processing, memory, and I/O resources for accomplishing management tasks. 

I/O stands for input/output. It is used to describe any program operation or device that transfers data from the computer to a peripheral device or vice versa. 

Primary memory is the computer memory that is directly accessible by CPU. It comprises of DRAM and provides the actual working space to the processor to perform its functions. It holds the data and instructions that the processor is currently working on.

A process in the main memory containing-

1. Stack- The containment zone for temporary data such as functional cells, local variables, and various other data is known as a stack.

2. Heap- It is the memory allocated dynamically during the run time.

3. Data- The global variables used in a program are stored in the data section.

4. Text- The program code used in a particular program is known as the text section.

Read more: What is a process state

What Is a Program?

A program can be defined as a system activity that uses a set of instructions for performing a designated task. It is considered a passive entity because it resides on the secondary memory of the system. The resource requirement in a program is less because it only requires memory for storage.

The contents of the secondary memory first get transferred to the primary memory and then are accessed by the processor. This is because the processor does not directly interact with the secondary memory unlike it does with the primary memory.

The tasks that are directly related to the operations of a user can be performed by the program. For better understanding, we can take an example- notepad.exe, that is an executable file that has a set of instructions that helps users to print and edit text files as well. When any user ought to execute a program, it converts into the process.

Read more: System programs in the operating system

Key differences between Process and Program

1. A process is defined as a program in execution, whereas, a program can be defined as a set of instructions.

2. Program is a definite group of order operations that can be performed. However, a program that is being executed is called a process.

3. The basic nature of the program is passive because it does nothing until it is executed by a user. On the other hand, the process is dynamic or active in nature because it’s the instance of executing the program and perform the specific action required.

4. A program can have a longer lifespan because it is stored in the secondary memory and it remains stored until it is not manually deleted by a user. A process, however, has a shorter and very limited lifespan because it gets terminated the second the task is executed.

5. A process requires much higher resources so that it could be processed and memorized, it also needs I/O resources for the successful execution. But in contrast, a program only requires memory for storage.

Conclusion

Program and process are two differential terms in operating systems such as Linux and Windows. They’re definitely codependent on each other and their concepts are simultaneous respectively. They are the pillars of the Operating Systems and thereby starting to learn OS needs a start from understanding these terms.

Read more: Types of Softwares Available 

Written By -  Pavas Shrigyan

Edited By - Neha Kundu