The Operating System (OS) is like the “central government” of the computer. It controls what happens on the computer, and provides basic services. Just like a government might provide water, roads, communications, and security, an OS provides video, keyboard, sound, printing, and network services.
For example, if you wish to make a house, you do not have to build roads, produce fresh water, create a telephone system, or hire a police force. All of these services are already available; you only have to access them when you build your home. In the same way, computer programs (also called "software" or "applications") do not have to communicate with the keyboard or mouse, create screen images, play sounds, or connect to printers or networks. All of these things are done by the OS; programs just ask the OS for the service, and gets access to them.
The three popular OS's available today are Windows, Mac, and Linux.
Before, it was necessary to buy a completely different computer in order to run a different OS. However, today, most computers can run most operating systems, so it is possible to run more than one OS on one computer.
The User Interface (UI) is how the computer presents itself to the user. All machines have an interface. For example, your car has the "driver's seat," where you can steer the car with a wheel and make it stop and go with foot pedals. People are used to having an interface that "makes sense," which allows them to "understand" and easily control the machine they are using. A well-designed user interface should be "invisible"; the user should be able to understand it naturally.
Originally, computer interfaces were extremely difficult to use. The first computers used various ways to "communicate" with the user, usually in the form of switches, blinking lights, punch-hole tapes and punch-cards.
The first "personal computer" (a computer cheap enough for a private citizen to purchase) was tha Altair, a computer with no mouse, keyboard, or monitor. Instead, the interface was switches and lights. To input data, the user turned switches on or off (1 or 0), and the computer "answered" by turning lights on or off (1 or 0).
Naturally, most people couldn't use this interface. To make computers easier, new UIs were developed.
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Early computers used a variety of ways to input data and to present output. These included punch cards, punch-hole tapes, and the early printers.
Early personal computers used the CLI, or Command Line Interface. These did not use a mouse or other object-oriented controls. You had to learn a hybrid human-computer language in order to operate the computer. If you used the wrong command or made a spelling mistake, the computer would answer with “SYNTAX ERROR” and could not do anything.
The CLI made computers more usable than before, but they were still difficult to use because you had to learn the special language used in the CLI.
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The GUI (Graphics User Interface) began in the 1960, when Douglas Engelbart developed the mouse, menus, and other GUI elements. These ideas were used by XEROX in a computer called the Alto, but that computer was never developed for sale. The first popular GUI computers were the Lisa and Mac computers developed by Apple in 1983 and 1984. Microsoft followed with Windows in 1985. The 1984 release of the Macintosh computer was the first big release of such an operating system, and Apple marked the event with their famous “1984” commercial (see YouTube version below). It was an artistic attempt to show how old, restrictive CLI computers were broken by the new GUI interface, using a vision of George Orwell's famous story “1984” as the background.
Important point: The GUI was truly a breakthrough because it allowed almost anyone to use a computer with relative ease. Instead of only computer technicians, now regular people could use a computer without any special training.
Multitouch
Most people consider the GUI to be "the way" to use a computer. It has been used for 25 years ("forever" in computer-time), and most people under 30 have never known anything different. But the GUI is far from perfect. The keyboard and the mouse are "disconnected" from what is happening on the screen. To test this, find and run a drawing program on a computer using a mouse. Try to draw a picture using just the mouse, a picture you can draw well by hand. You will find the mouse-drawn image clumsy and childish-looking, as if you drew with the wrong hand. This demonstrates that the mouse is not really a good controller.
The newest OS type is multitouch. A touch screen can only sense one finger or a "stylus" (pen) touch. "Multitouch" can sense many different contact points at the same time.
A multitouch OS is superior because it allows the user direct access to the computer, giving the most natural way to control a device. A child will take to this naturally, and you will even see videos of animals using a multitouch computer!
Major Operating Systems
There are three "major" operating systems, and a new kind of OS: the mobile OS.
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Windows
Originally based upon Microsoft's MS-DOS CLI OS, Windows is the most popular OS today. About 90% of computer users worldwide use Windows–but that number is dropping.
Whether Windows is the "best" is an argument made by various users. Windows gained its popularity because of the aggressive business model used by Bill Gates and Steve Ballmer at Microsoft. The actual Windows OS, however, has often lagged behind the Mac OS and Linux in terms of new features and usability.
Microsoft released Windows XP in 2001, and did not release another new version for 6 years. While XP was considered a good OS, six years is too long without a major upgrade. The Mac OS was upgrading to new versions every 1.5 ~ 2 years, and XP was becoming dated. However, Microsoft was not ready with their new version yet.
Unfortunately, they released a new version anyway--Windows Vista--too early, before it was really finished. Because of the premature release, many users had problems. Some peripherals, like printers, would not work with Vista, and many people suffered crashes and other bugs. Vista was so unpopular that many people would demand their new computers have XP installed instead. Most Windows users continued to use XP, even when it was 8 or 9 years old--ancient in computer terms.
Another problem with recent Windows OS releases has been the fact that it comes in too many versions--"Starter," "Home," "Business," "Enterprise," and "Ultimate"--as well as "Basic" and "Premium" varieties of some of those types, and 32-bit and 64-bit versions as well. Each one has different levels and sets of features, and the price ranges from $150 to $400. It makes it difficult and confusing for customers to understand which version they should buy; in contrast, the Mac OS has only one version, usually for $130 (sometimes as cheap as $25), which has all the features.
Microsoft finally released "Windows 7" in mid-2009. Windows 7 is considered a mature and stable OS version--what Vista should have been, but was not. Windows 7 is often called "Vista Service Pack 2," a reference to the idea that 7 is just a repaired version of Vista. In addition to Vista's new graphic interface (sometimes called "eye candy") and features like Desktop Gadgets, Windows 7 introduces a new Taskbar (which can have apps "pinned" to it), new windows management including a feature called "Jump Lists."
Although Windows 7 is much more stable and popular than Vista, many people still have the image of post-XP Windows as being unreliable, and so new user adoption remains somewhat slow.
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The Mac OS was the first to have a GUI; based upon the 1983 Lisa computer, the Mac used all the familiar elements of the GUI: a desktop, windows, icons, menus, mouse clicks, and dialog boxes.
Although Apple computers had a large market share in the late 70's and early 80's, company mismanagement and expensive pricing caused Apple's Mac computers to fall to only 3% of all computers used, even though many believed that the OS was always superior to Windows. Today, 10% of computer users have Apple computers, and the market share is growing.
In the late 1990's, Steve Jobs, who founded Apple Computer back in the 70's but was pushed out in the 80's, returned to Apple. He brought with him many new ideas to bring new life to the company. The Mac OS was completely redesigned, based upon the strong and well-established UNIX OS, and was renamed "Mac OS X." Jobs also made other decisions that helped the company succeed, including the creation of the iPod, iPhone, the iTunes Store, and the introduction of advanced design concepts that changed how computers looked.
Part of the Mac's recent popularity is the switch to Intel CPUs, which allow Mac computers to install Windows and run the two OS's side by side. In short, you can run both the Mac OS and the Windows OS on one machine.
Apple's Mac OS is called "OS X" ("Oh Ess Ten"), and is updated much more often than Windows (usually every year and a half), and is counted by "point" releases along with the names of big cats: 10.3 was Panther, 10.4 was Tiger, and the current OS, 10.5, is Leopard. Major features in recent OS X releases include Exposé, a graphic way to switch between windows; Spotlight, an advanced and very fast search feature; Quick Look, a way to instantly preview files; Dashboard, a way to access many mini-programs quickly; and Time Machine, a backup utility.
The next version of OS X is 10.6, named "Snow Leopard." As the name suggests, it is less than a full version upgrade. Instead of adding new features, it concentrates on system performance, making the OS smaller and more efficient and better able to take advantage of new technologies.
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Linux is an open source OS created by Linus Torvalds, and like Mac OS X, is based on UNIX. Because it is open source, it is free, although you sometimes have to pay a price (much lower than Windows or Mac) for versions which are easy to install.
Linux was originally only an OS for "geeks," or computer hobbyists, but recent versions, such as Ubuntu (pictured below) are easier to use, and someone without much computer experience can handle it without much trouble.
Despite being cheap or even free, only 1% of computer users run Linux. Linux remains popular with system administrators (people who control large computer networks), and many companies and governments are switching from Windows to Linux as a way to save money, increase security, and avoid Microsoft's control.
Mobile Operating Systems
A relatively new kind of OS is one specifically made for smartphones. Previously, many cell phones had their own OS software, different for each phone, and not very structured or well-organized. The most commonly used was Windows Mobile OS, which was generally considered to be of very poor quality. When Apple released its iPhone, it came with an OS with a very specific style and feature set. Like regular operating systems, the OS is used across many products (iPod Touch, iPhone, and iPad), advances with new versions (currently 3.2, with iPhone OS 4 coming soon), and is a platform for growing new features and services.
After Apple came out with the iPhone OS, Google created the Android OS. While Apple's OS was only for Apple products, Android was intended for use by any cell phone maker that wished to use it. Android had more features (such as multitasking), but was considered more buggy.
Recently, Microsoft announced its own new mobile OS, called "Windows Series 7." This OS is still under development, and may not be released until the end of the year. Like Android, it will be used by many different phone makers.
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Beginning with the iPhone, these new mobile operating systems have something considered highly valuable: an App Store. With normal computers, buying apps is a disorganized process. Software is available in many forms, from many places, and is capable of doing almost anything. It is uncontrolled, and sometimes dangerous--some software can contain viruses, adware, or spyware, for example. Prices are usually high because most people pirate (steal) their software, forcing software makers to sell for high amounts to make up for this.
Apple changed that with the iPhone OS. Their app store is very strictly controlled. Apps must be submitted to Apple, which approves each one after a review. Once it is approved, the app is then sold only through Apple, which takes 30% of the sale price. This sounds strict, but there are many important advantages. There are no viruses or malware, and most apps run very well. Since the system is "locked" by Apple, piracy is not usual and so software is much cheaper. Software is also very easy for customers to find, because it is all in one place, where you can search, read reviews, and buy through the iTunes software. This makes it easy for amateur programmers to create and sell software, something that was very difficult before. As a result, there are now more than 170,000 apps for the iPhone OS.
Android has the "Android Market," with 50,000 apps for its OS. Windows Series 7 will have its own app store as well.
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