4.1 The Operating System
4.1.3 Operating system types - basic terminology
To understand what an OS is capable of, it is important to understand some basic terms. The following terms are often used when comparing operating systems:
  • Multiuser – Two or more users running programs and sharing peripheral devices, such as a printer, at the same time.
  • Multitasking – The capability of a computer to run multiple applications at the same time.
  • Multiprocessing – Allows a computer to have two or more CPUs (Central Processing Unit) that programs share.
  • Multithreading – The capability of a program to be broken into smaller parts that can be loaded as needed by the OS. Multithreading allows individual programs to be multitasked.

Here is a list of some of the most popular operating systems:

  • Microsoft Windows 95, 98, ME – Windows is one of the most popular operating systems today. Windows is designed to run on PCs and to use an Intel-compatible CPU. Windows-based PCs use a Graphical User Interface (GUI) as the interface between the computer and the user.
  • Microsoft Windows NT/2000/XP – Also from Microsoft, Windows NT, 2000 and XP are operating systems that were designed to support multiple (concurrent) users and to run applications simultaneously. Both Windows NT and Windows 2000/XP have incorporated many networking features.
  • The Macintosh OS – The first Macintosh computers became available in January of 1984 and were designed to be very user-friendly compared to the existing DOS computers. The latest release of the Macintosh Operating System, OS X, is highly functional and is based on UNIX as its core technology.
  • UNIX – UNIX, which has been around since the late 1960s, is one of the oldest operating systems. UNIX has always been popular with computer professionals whose responsibility is to run and maintain computer networks. UNIX-based computers from IBM®, Hewlett-Packard (hp), and SUN® have helped run the Internet from the beginning. There are many different versions of UNIX today. One of the most recent is the extremely popular Linux.

Windows, UNIX, and Macintosh operating systems are proprietary operating systems, meaning that they must be purchased. On the other hand, Linux may be copied freely and has recently gained acceptance with IT professionals. As UNIX-run computers have become more powerful and graphical user interfaces have become available, Linux has gained in popularity with individual users. Operating systems are constantly under development and new versions are released when they are completed. As new ones become available, older ones eventually become unsupported.

Worksheet  (PDF, 6 KB)
  Operating System Fundamentals