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by ComputerBob
February 16, 2002
Several times each semester, students who want to buy a word processing program ask me, "Do you think I should buy Office XP or Windows XP?"
If you don't know the answer to that question, then this article is meant for you.
Nearly every personal computer consists of a plastic or metal box that contains a central processing unit (the main "brain" of the computer) along with circuit boards, integrated circuits, some temporary storage (RAM memory), at least one permanent storage device (usually a floppy disk drive and/or a hard drive), a power supply, and various other physical components and devices. Outside of the personal computer's box, there are other devices that allow interaction with the computer. The keyboard and mouse, allow the user to tell the computer what to do, and a monitor (TV screen), speakers, and printer, allow the computer to tell the user what it is doing. All of those physical parts of a computer are known as hardware.
All by itself, hardware is just a bunch of mechanical and electrical parts that are connected to each other -- those parts don't know what to do or how to do it. They need to be told what to do and told how to do it.
Imagine your car. It's a pretty complicated piece of technology, containing thousands of pieces of mechanical and electrical hardware that are all connected. But by itself, your car doesn't know what to do or how to do it -- it just sits there in your driveway. If you want your car to take you somewhere, you have to sit in it, step on its pedals, turn its steering wheel, and manipulate its various controls, to tell it what to do (go forward; go faster, go slower; turn left; stop).
So, how does your car know that you want it to go faster when you step on its accelerator pedal? Because your car's manufacturer built it to include a set of permanent instructions that tell it to increase the timing of its spark plugs and send more fuel to its engine every time you step on its accelerator. Because your car has a set of permanent, built-in instructions, you don't have to know anything about spark timing or air-to-fuel ratios in order to drive your car. You just manipulate its controls (gas pedal, brake pedal, steering wheel, etc.) to tell it what to do, and its built-in instructions tell it how to do it.
Like your car, your computer is a complicated piece of technology, containing hundreds of pieces of mechanical and electrical hardware that are all connected. And, just like your car, your computer's hardware just sits there unless something tells it what to do and how to do it. In the same way that you drive your car to tell it what to do, you manipulate your computer's controls (keyboard, mouse, etc.) to tell it what to do. So, how does your computer know how to print a document, underline a word that you've typed, browse the Internet, or check your email? The answer is that, just like your car, your computer uses a set of instructions that tell it how to do what you tell it to do. In a computer, that set of instructions is called software. People who design software are called software designers, while people who write the software's step-by-step lines of instructions that tell the computer how to do things are called programmers. Because your computer can run software that other people have designed and programmed, you don't have to know anything about software design or programming in order to use your computer. You just manipulate its controls to tell it what to do, and its software tells it how to do it.
If your computer's manufacturer had built it with a set of permanent, built-in software, you'd be able to turn it on and it would instantly be ready to do whatever you wanted it to do, like your car. You wouldn't have to wait for it to "read its instructions." So, why don't personal computer manufacturers build their computers with permanent, built-in software? The fact is that many handheld, personal organizer computers come with permanent, built-in software. While that idea works with small, limited-function computers, it wouldn't be a good idea for home or business computers because there are hundreds of thousands of different pieces of software in the world, and because people like you want to be able to choose which software they will use. So, instead of forcing everyone to use the same software, your computer's manufacturer built your computer without any permanent, built-in software, but with the ability to run whatever software you choose to install on it.
There are two main types of computer software: operating systems and applications. Your operating system is the software that automatically loads from your computer's hard drive into its short-term memory every time you turn on your computer. That's why you have to wait a minute or two after you turn on your computer before you can actually use it -- you're waiting for it to "read its instructions."
Your computer's operating system is a set of instructions that tells your computer how to do general tasks, such as
I always tell my Computer Literacy students that an operating system is the software that teaches your computer how to be a computer, instead of a door stop.
If the only software on your computer is an operating system, you won't be able to do very much with your computer. Your computer's operating system doesn't know how to do check your email, browse the Internet, create a financial spreadsheet, or do any of the hundreds of other specific tasks that computer users need to be able to do with their computers.
In contrast to an operating system, which tells your computer how to do general tasks, an application is a set of instructions that tells your computer how to do a specific task, such as
In addition to selling applications separately, software publishers often sell several of their applications together in one package, called a software suite. For example, Microsoft Office XP Professional is a high-end, feature-packed software suite that includes Word, Excel, PowerPoint, Access, and Outlook all in one package, sold at a significant discount from what you would pay if you bought each of them separately. Oten, students confuse Microsoft Word with Microsoft Works. Microsoft Word is a feature-packed, high-end word processing application. In contrast, Microsoft Works is a very basic software suite that's kind of like a children's version of the Microsoft Office software suite. Works has its own word processor, spreadsheet, etc., but they are all very simple, low-end applications. For that reason, students who take courses in Microsoft Office applications need to use the full-blown Microsoft Office applications -- they cannot use the low-end Microsoft Works applications.
If you go back and read the list of some of the operating system's tasks, you'll see that they are all general tasks that are needed by all of the specific applications on your computer. That means that you don't have to tell each of your applications what kind of hardware your computer is using. You only have to tell your operating system. For example, you don't have to tell your word processing application what kind of printer you're using, you just have to tell your operating system. Then, any time you tell your word processing software to print a report, it doesn't have to know what type of printer you have. All it has to do is format the report the way you told it to, and then give it to the operating system, which knows how to send it to your printer.
The other side of that coin is that, without an operating system, your applications are useless. If your computer doesn't have an operating system, it won't even know how to install your applications, let alone run them or provide general services to them. That's why your computer has to load its operating system first, every time you turn it on, and the operating system has to be running all the time until you turn off your computer -- so that your computer will know how to load and run your applications, and it will know how to do all of the basic tasks that your applications will need it to do.
There are several competing choices in the operating system field, but by far, the most popular operating systems for both home and business personal computers are the various flavors of Microsoft Windows.
MS-DOS was the first operating system that Microsoft created to run on personal computers. A computer running MS-DOS greeted its user with a black screen and a flashing white cursor. The user was expected to know hundreds of commands to type into the computer, to make it perform its functions. If the user mistyped a command, the only feedback they would receive would be a message that would appear on the screen, telling them, "Bad command or file name."
Microsoft created its 3.x versions of Windows to add onscreen icons, menus, and other graphical features to MS-DOS. The first versions of Windows were not very powerful, and ran much slower than MS-DOS had run, because Windows had to interpret every mouse click and turn it into a MS-DOS command, so that the underlying MS-DOS would know what to do. Despite their often infuriatingly slow speed, people used the first versions of Windows anyway, because they were much easier to use than MS-DOS had been. Back then, both home and business users used essentially the same version of Windows, though the business version had some networking capabilities and was called "Windows for Workgroups."
| Home Operating Systems | Business Operating Systems |
|---|---|
| MS-DOS | MS-DOS |
| Windows 3.x | Windows For Workgroups |
| Windows 95 | Windows NT 3.x |
| Windows 98 | Windows NT 4.x |
| Windows ME | Windows 2000 |
| Windows XP (versions for home and business) | |
Windows 95 and the first versions of Window NT were introduced at about the same time, with the former designed for home use and the latter for business use. Windows 95 was designed to use many more multimedia devices, while the much more expensive Windows NT had many more security and networking features. Those two operating systems introduced a significant split between Microsoft's home and business operating systems, because they each used a different kernel (an operating system's basic programming code). The Windows NT kernel, aimed at businesses, was much more stable and secure than the Windows 95 kernel, because the latter had been designed to work with as many more devices, and run many more pieces of older software. A few months after releasing Windows 95, Microsoft released Windows 95 OSR2 (OEM Service Release 2), which fixed several bugs that had been present in Windows 95 while adding a few networking features and the ability to save files onto a hard drive more efficiently.
Windows 98 was little more than a compilation of all of the bug fixes that Microsoft had created to fix Windows 95's problems. Windows 98, Second Edition (SE), was little more than nicer looking icons and a compilation of Windows 98 bug fixes. Fortunately, many of those bug fixes were significant ones, making Window 98 SE a relatively stable operating system compared to its older siblings. Both versions of Windows 98 used the same basic kernel that had been used in the original Windows 95.
A lot of professionals believed that Windows ME was released mainly to make more money for Microsoft, because it added very few features to Windows 98 SE, while introducing several new bugs of its own to the Windows 95 kernel. For that reason, most professionals chose to keep using Windows 98 SE, instead of "upgrading" to Windows ME. In fact, I still run Windows 98 SE on my home computer, which I used to write this article.
Windows 2000 added several security and networking features to the Windows NT kernel, along with a nicer looking user interface.
Windows XP was Microsoft's first attempt to reunite their long-separated home and business operating systems under one new software kernel, with a new, friendlier look and feel. By creating both a home and a more expensive business version of Windows XP, Microsoft hoped to improve the stability, networking, and security of their home operating system, while improving the mulitmedia capabilities of their business operating system. Time will tell whether or not they succeeded in that effort. Though they have very similar names, don't confuse Microsoft Windows XP with Microsoft Office XP. The former is an operating system, while the latter is a suite of applications.
Getting back to the whole reason that I wrote this article, now you know the difference between hardware and software, and between an operating system and an application. You also know that hardware by itself, an operating system by itself, or applications by themselves, are useless. Your complete computer system needs hardware, an operating system, and applications in order to do the things that you need it to do.
imagine that your telephone just rang. It's one of your friends, and they say:
"I'm thinking of buying a new word processor. Do you think I should buy Microsoft Office XP or Windows XP?"
What are you going to tell them? 