Process

A process is a program that is currently being executed on a computer.

It is almost the same as a task, which is the unit of work scheduled by the CPU.

When a program is loaded into memory, it becomes an instance of a process,

and then the CPU executes it according to the operating system's scheduler.

 

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Memory Structure of a Process

When the OS allocates memory to a process, it follows this structure:

 

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Stack and Heap (Dynamic Allocation)

Allocated at runtime.

• Stack: It stores local variables, parameters, and function call information, growing and shrinking as functions are called and return.
• Heap: It stores dynamically allocated data, such as objects and arrays.

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Data Segment and Code Segment (Static Allocation)

Allocated at compile time.

• Data Segment:
  • BSS Segment: Holds global/static/const variables initialized to 0 or uninitialized.
  • Data Segment: Holds global/static/const variables initialized to non-zero values.
• Code Segment: Contains the program’s executable code.