Basic Structure of OS

• Whatever we see on screen is User Area (User mode or non-privileged mode).
• Whatever happens behind the screen is Kernel Area (Kernel mode or privileged mode or system mode).

Operating System

Operating System (OS) is a software that gives Graphical User Interface (GUI) and do basic functions like task scheduling, controlling peripherals, etc.

Types of OS

1. Serial Programming Operating System

Serial programming OS can load only one task at a time.

2. Batch Programming Operating System

Batch OS can load more than one task from memory, but it can execute only one task.

3. Multi-Programming Operating System

Multi-programming OS can load only one task from memory and execute it. But when that task needs I/O operation then it load second task from memory and execute it.

4. Time Sharing Operating System

Time sharing OS can execute more than one task but not at a time. It switches the tasks. The switching process is very fast that we receives immediate response.

5. Multi-Processor Operating System

Multi-processor OS share common physical memory. OS divides main task into many sub-tasks and executes those sub-tasks parallel in different processor. 

6. Distributed Operating System

Distributed OS uses central processors. Tasks are distributed among the different processors according to which can perform more efficiently.

7. Real Time Operating System

Real time OS gives maximum time to critical tasks like interrupt handling.

8. Embedded Operating System

Embedded operating system is a specialized OS for use in the computers built into larger systems.