Different Types of Operating Systems:- UNIX

3. Different Types of Operating Systems:- UNIX

Different Types of Operating Systems:- UNIX

• UNIX

   UNIX is a multiuser operating system with a character user interface. UNIX also has invited tree structure. Main features of UNIX are:-

   (1) Multitasking Capability

   (2) Multiuser Capability

   (3) Portability

   (4) Security

   UNIX has three main components:-

1. Kernal:-

   Kernal is the heart of the UNIX operating system which performs all the low-level jobs to control the tasks and scheduling of devices and manage the processes.

2. Shell:-

   Shell is a command interpreter of the UNIX operating system. It accepts commands from the user at the "$" prompt and analyses and interprets the commands.

3. Tools and Applications:-

   UNIX tools are used from the command line and help to perform simple and complex tasks. These tools include ser of application programs.

   UNIX file system begins with the main directory root and followed by other subdirectories. The root directory contains bin, etc, dev, usr, lib, and temp subdirectories. Root directory in UNIX is donated by (/) Slash symbol.

   Kernal is the master program that controls the computer resources allotting them to different users and to different tasks. Kernal does not directly deal with the user. It starts up a separate interactive program, called shell for the user who logs the system. Then shell acts as an interface between the user and the system.

NOTE: The Kernal and the shell work together to provide UNIX services.