The operating system is a master program that controls the functionality of computers and the management of computing resources. it is vital to have a deep understanding of the operating system.
This lesson introduces you to the general understanding of operating systems, their types, license, structure, and functions based on their availability in terms of command line and graphical user interfaces.
What is an Operating System?
Operating System is system software that manages computer hardware and software resources and provides common services for computer programs. The OS controls hardware devices such as the disks, keyboard, mouse, monitor, etc, and allows the user's programs and packages to be run on the machine.
Operating System and Computing Resources
Operating System (OS) is the master control program that manages all computer resources. Without OS, all hardware would just sit there and collect dust. The operating system is a program that manages computer hardware. First computers did not have OS, they had programs that were directly loaded into the computer (e.g. punchcards). Today, computers have an OS that loads into the computer's memory during its startup.
The gui and cli based Operating systems
Operating systems are available with either Graphical User
Interfaces (GUI) or Command Line Interfaces (CLI). Most computer users run
Microsoft Windows, Mac OS, or Linux as their OS because they are Graphic User
Interface (GUI). A GUI-based OS allows users to control computers using a Mouse
and Icons. Without a GUI, the user controls the computer using the keys on the
keyboard. This is referred to as a Command Line Interface (CLI).
The GUI based Operating Systems
Some of the GUI-based OS includes all MS Windows, some Linux
distributions, and macOS. MS Windows is the most common OS used in the market
by various end-users. Various versions of MS Windows include Windows 95,
Windows 98, Windows Millennium Edition (Windows ME), Windows NT, Windows 2000,
Windows XP, Windows Server 2003, Windows Vista, Windows Azure (Cloud OS
Platform), Windows Server 2008, Windows
7, Windows Server 2008 R2, Windows Server 2012 R2, Windows 8, Windows Phone,
Windows 10, Windows 10 Mobile, Windows Server 2016, etc.
Some of the CLI-based OS include Linux, UNIX, and Microsoft DOS (MS-DOS). The MS-DOS stands for Microsoft Disk Operating System and is a single-user operating system. The CLI-based OS basically means that you enter commands at a prompt (command line) and the system responds to your commands. If you enter commands that the system does not understand it gives you an error message. It indicates that the user should basically know or memorize the commands to be able to use the computer.
When you turn on the computer, the computer will eventually
come up with a prompt called the command prompt.
With the advent of GUI-based OS, the idea of using command line prompt and type-in commands at the keyboard is considered by many people as quite old-fashioned. Why get trouble memorizing commands and their syntax when you can just select them from menus?
In CLI-based OS, users are allowed to group related files together in a form of directories. A directory is a file folder container that can contain files and other directories. Every file is stored in a directory. A directory contained within another directory is called a child or subdirectory. The subdirectory can in turn contain other directories and files, etc. A file contains information that can be read, modified, or even deleted. A directory acts only as a container and therefore container does not contain information. Files are organized on a disk by the directory structure. The root of the directory structure is at the top. The root of a disk drive is represented by the backslash (\). To completely specify a file on your computer you must specify its drive and directory path, and its filename. However, a file does not always have to be specified in this complete form; if it is in the current directory, then you can just enter its filename.
The function of the Operating System
Computer functions are based on its OS. Within OS, drivers (responsible for the functioning of a computer) and various utility programs (responsible for the functionality of a computer) are installed.
The OS allocates resources based on user needs and the system’s capability. The four (4) major functions of OS are:
(i) File and Software Management
(ii) Input/Output and peripheral Management
(iii) Memory Management,
(iv) CPU Management.
The OS acts as an interface between the hardware of the computer and the application software that users need to run.
The OS controls I/O or directs the flow of information to and from the CPU. When you turn ON your computer, it first needs to load OS, a process known as booting up. Once the system is loaded the user can start the application or program that they are going to use.
Types of Operating system
The most famous operating systems are:
(i) Linux (Debian, Ubuntu, Fedora, Knoppix, etc.) which is open-source software (OSS),
(ii) Microsoft Windows (XP, Vista, 7, etc.) which is a proprietary software
(iii) Mac OS X (Cheetah, Panther, Snow Leopard, etc.) which is also proprietary software. Other examples of OS include Apple, Control Program for
Microcomputers (CP/M), PCDOS, MSDOS, UNIX, O/S2, and various others.