System software forms an interface between software applications, such as a word processing program or an Internet browser, and computer hardware, including peripherals such as printers.
System software is often invisible to users because it is what gets the computer booted up so that users can do interesting things. Yet without this software, the computer would not run. For example, a printer hooked to a computer requires a certain kind of software called a "driver." Anyone sending a document to the printer would not be aware of this software unless it was not installed, in which case the document wouldn't print. Even hardware that is part of the computer, such as a trackpad on a laptop, requires a driver. Another example of system software would be the programs used to manage a computer, such as installing or removing software and the programs that create the desktop environment. There are three major brands of system software in use and many smaller brands as well. One of the most well known is Windows, which is published by Microsoft and often installed on computers before a customer buys them. Another brand is iOS, which is installed on Apple computers. A third well-known group of system software is Linux. There are many different versions of Linux, tailored made to different people's needs.