Program and Process in operating systems

 What is Program?

A program contains set of instructions and set of instruction perform some specific task for the user.

  • A program is stored on secondary storage. For example a program is stored in hard disk in computer.
  • When we execute the program, the program coverts into the process.

What is process?

Process is the program in execution.

  • How a program is converted into process?

    • Program can be convert into the process by following three actions;
      • Compiler
      • Linker
      • Loader

What  is Compiler?

Compiler converts the high level language code into the low level language code or  object code.

Compiler creates the .o file.

What  is Linker?

Linker converts the object code or low level language code into the executable code.

Linker creates the .exe file.

What  is Loader?

Loader loads the executable code into the main memory and allocates the address space for the process.

  • A program contains code and data section.

What is code section of the program?

Code section of the program contains the program instructions or lines of code.

What is data section of the program?

Data section of the program contains the data of the program.

For example, it contains all the initialized variables in the program etc.