Systems software includes any instructions or programs that are used to manage and control computer functions. Systems software is an es­sential part of the computer system because it manages and controls the hardware so that the application software can perform a task. These programs enable the computer to start operation, launch application programs, and facilitate im­portant jobs, such as transferring files, configur­ing the system to work with a specific brand of printer or monitor, managing files on the hard drive, and protecting the computer system from unauthorized use. Systems software is usually divided into two categories: operating system software and utility programs e.g. disk defragmenter, file compression.

Operating system software for computers

An operating system (OS) is the most important software that runs on a computer. It manages the computer’s memory and processes, as well as the software and hardware. It allows you to communicate with the computer without knowing how to speak the computer’s language. Without an operating system, a computer is useless.

The OS manages the software and hardware on the computer. Most of the time, there are several different computer programs running at the same time, and they all need to access the computer’s central processing unit (CPU), memory, and storage. The OS coordinates all of this to make sure each program gets what it needs.

Operating systems usually come pre-loaded on any computer you buy. Most people use the operating system that comes with their computer.  It is possible to upgrade or even change operating systems. Each operating system’s graphic user interface (GUI) has a different look and feel.  If you switch to a different operating system it may seem unfamiliar at first.  Modern operating systems are designed to be easy to use, and the basic principles are the same. The three most common operating systems for personal computers are:

Microsoft Windows – Microsoft created the Windows operating system in the mid-1980s.  There have been many different versions of Windows, with the most recent one being Windows 10 which was released in 2015).  Other versions include Windows 8 (2012), Windows 7 (2009) and Windows Vista (2007).  Windows comes pre-loaded on most new PCs which helps to make it the most popular operating system in the world.

macOS – macOS (previously called OS X) is a line of operating systems created by Apple. It comes preloaded on all Macintosh computers, or Macs. Some of the specific versions include Mojave (released in 2018), High Sierra (2017), and Sierra (2016).

According to StatCounter Global Stats, macOS users account for less than 10% of global operating systems—much lower than the percentage of Windows users (more than 80%). One reason for this is that Apple computers tend to be more expensive. Many people do prefer the look and feel of macOS over Windows.

Linux – Linux (pronounced LINN-ux) is a family of open-source operating systems, which means they can be modified and distributed by anyone around the world. This is different from proprietary software like Windows, which can only be modified by the company that owns it. The advantages of Linux are that it is free, and there are many different distributions—or versions—you can choose from.

According to StatCounter Global Stats, Linux users account for less than 2% of global operating systems. Most servers run Linux because it’s relatively easy to customize.

Modern operating systems use a graphical user interface, or GUI (pronounced gooey). A GUI lets you use your mouse to click icons, buttons, and menus, and everything is clearly displayed on the screen using a combination of graphics and text.

Operating systems for mobile devices

Mobile devices such as phones, tablet computers, and MP3 players are different from desktop and laptop computers, so they run operating systems that are designed specifically for mobile devices. Examples of mobile operating systems include Apple iOS and Google Android.

Operating systems for mobile devices generally are not as fully featured as those made for desktop and laptop computers, and they are not able to run the same software. You can still do a lot of things with them, like watch movies, browse the Web, manage your calendar, and play games.