The document explains the major concepts of an operating system kernel, highlighting its role as an authority over CPU, I/O devices, and hardware resources. It elaborates on the function of a shell as a command line interface that interprets user instructions into binary for the kernel, and describes system calls as requests for computer resources. Finally, it distinguishes between command line interfaces (CLI) and graphical user interfaces (GUI) as methods of interaction with operating systems.

1. Major Concepts of
Operating System

2. Kernel:
A kernel is a authority over CPU (Central Processing Unit), I/O (Input &
Output) devices and hardware resources. Kernel is a authority that acts
upon the instructions given to it by CLI (Command Line Interface) or
GUI (Graphical User Interface). Kernel accepts and passes
corresponding instructions in binary language (which is the native
language of computer).

3. Shell:
Shell is a CLI (Command Line Interface) that works as interpreter. It
receives an instruction through a command and translates it in a binary
form before passing it to the kernel of the operating system. It
interprets each command at each system call.
System Call:
A mechanism (method) in which we request a resource or resources of
computer through kernel is called system call.
These resources may include CPU (Central Processing Unit), I/O (Input
& Output) devices and hardware resources.

4. Operating System:
“An Operating System (OS) is a software that acts as an interface
between computer hardware components and the user.”
OS

5. Example of Interface:
Here, google translator is interface between the English and the Spanish.

6. Types of Interface in Operating System:
In operating system, there are two types of interfaces these are as
under:
• CLI (Command Line Interface): This type of interface provides a way
of interaction with computer resources by issuing commands.
• GUI (Graphical User Interface): This type of interface provides a way
of interaction with computer resources through graphical platform.

7. Operating System
(CLI or GUI)
Kernel
Resources of Computer
Architecture of Operating System