Chapter 3 - What is this thing?

The computer often mystifies people. It is an incredible device that does things not even dreamed possible just decades ago.

But like any invention, it's made up of parts that perform specific functions. You can better learn how to operate a computer if you have a basic understanding of its parts and what they do.

Computers, PCs and Macs, oh my!

In simple terms, a PC is short for personal computer, but over the years the acronym has taken on another meaning (besides "politically correct").

The first machine to be called a personal computer was the IBM PC in 1981. The company eventually licensed its technology to other companies who started making cheaper clones, and the term PC came to represent any "IBM-compatible" computer. Today, for all intents and purposes, if a computer runs a Microsoft Windows operating system, it qualifies as a PC, and PCs now comprise more than three-quarters of the home computing market.

Although Macintosh systems are personal computers, they're not commonly referred to as PCs. They're called Macs, and they're all made by one company, Apple. Macs are the computers of choice in most school systems, as well as such creative arts fields as graphics, film and music.

Let's avoid taking sides on the long-standing Mac versus PC debate (That wouldn't be politically correct now, would it?). If you want an objective look at the pros and cons of each before heading to the store, see "Appendix A - Buyer's Guide and Setup."

Another big distinction among computers is whether they are in the desktop/tower or the laptop/notebook category. Desktop or tower machines consist of separate components that connect to each other and typically sit atop or below a desk. The more common tower box is tall and thin like a skyscraper while the older-style desktop box sits flat and is more akin to a one-story building.

Laptop and notebook computers, which can run on batteries or AC power, combine all their components into a portable design. If you travel or need to move your computer between locations, a laptop or notebook is the preferred choice.

For now, let's all act as one big, happy family and just call them all computers.

Looking it over

Our tour of the computer starts with a brief overview of the different parts that are visible. All of this stuff is classified as "hardware," because it can be picked up and thrown around. (Warning: most warranties don't like when things are thrown around.) "Software," on the other hand, is a term for the games, word processors and other programs that you run on your computer. Programs are nothing more than instructions telling your computer what to do.

The monitor

Like its predecessor the TV, the computer monitor is often the first thing that grabs your attention. It's just like a television, although it provides a sharper picture and promises not to air any "Dancing With The Stars" footage.

Most monitors sit separately from the main guts of the computer and are now typically 17- or 19-inch, with a small few of us blessed with 21-inch models. As with TV-sets, those numbers are supposed to be the diagonal measurement of the screen, but almost all of them lie by about an inch and a half.

Most new computers today will ship with flat-screen LCD (liquid crystal diode) monitors, which are lighter and flatter than the older CRT (cathode ray tube) monitors. CRT monitors are boxy, heavy and take up more desk space.

Unless you're talking about a laptop, notebook or iMac - in which the screen and computer are physically attached, the monitor has to connect in two places. It needs lots of power, so it must plug into the wall socket or power strip. And it needs to know what to display, so it has a special video cable to connect into the main box of the computer.

A monitor is considered an "output device" because you don't give information to it; it gives information to you. It's kind of like that annoying neighbor who always talks and never listens.

The keyboard

If the monitor is considered an output device, then the computer keyboard would logically be an "input device" - and it is the main one. Like a good friend, the keyboard will listen to everything you have to say, but it likes to gossip, so it'll pass each letter and number you type through a cable to the computer. It's not an output device, so it won't talk back to you.

Most computer keyboards plug into the back of the computer, but if you like to lean back in your chair while typing, you can get a wireless keyboard.

If you're looking at a computer keyboard for the first time, you'll notice that all of the letters and numbers, as well as the space bar and the Tab key, are in the same place as on a manual or electric typewriter. (Thank goodness they didn't make us re-learn typing!)

You'll also notice a bunch of extra keys. Both Macs and PCs add an additional numeric keypad at the far right, which makes it easier to type in a lot of figures for, say, balancing our checkbook. They've also add a row of keys marked F1, F2, etc. across the top of the keyboard. These often perform functions based on whatever program you're running at the time.

Look to the right of all the letter keys and you'll notice a section with arrow keys, Page Up, Page Down, Home and End. These will help you move around the screen, and they'll be covered in more detail in "Chapter 6 - Navigating the desktop."

As you'll probably recall from Typing 101, if you want a lower case a, you just hit the A key, but if you want a capital A, you hold down Shift and hit the A key. That standard doesn't change in the computer world. And, as with regular typewriters, there's also a Caps Lock key that lets you type capital letters without holding down Shift.

So IF YOU FIND YOURSELF SUDDENLY TYPING IN ALL CAPS, you've probably accidentally hit the Caps Lock key. Hit it again and you'll be back to normal.

While we're on the subject of shifting, let's look at some specialized keys that work similar to Shift and sit in the same area, to the right and left of the space bar. On PCs, they're called the Alt and Ctrl (pronounced "control") keys. On Macs, they are the Control key, the Option key and the Command key (that button with a little cloverleaf symbol).

Like Shift, these keys do nothing by themselves and have to be held down while hitting another key. So if you're on a PC and someone tells you to hit Ctrl-C to copy, hold down the Ctrl key and hit C. If you're operating a Mac and a manual instructs you to use Command-Z to undo, hold down the Command key and hit Z. Don't worry about having to remember these commands now. Just know how to use them.

Many PC users will also notice a few additional keys near the space bar - one or two keys with the Microsoft Windows logo and another with a box and an arrow. These are specific to Windows and will be covered in later chapters in this section.

The mouse

The computer mouse, like the keyboard, is an input device - meaning by using it, you're talking to the computer. But it's a different breed of input device because its movement is mimicked on-screen by a tiny pointer called a cursor.

The mouse got its name because the device resembles the tiny rodent, but the electronic version has a longer tail (cord) that plugs into the main computer. You can also get a wireless mouse to avoid tangling the tail. By rolling the mouse around on a flat surface (your desk or a mouse pad), you're moving the cursor around the screen. And by "clicking" the mouse's buttons, you're selecting things on the screen.

Some mice (or is it mouses?) roll around using a little tiny ball that protrudes from the bottom. Newer ones use a lighted optical eye that detects movement. Both work fine, but the latter won't allow dust and dirt to slow you down as with a ball-type mouse.

With laptops and notebooks, there's seldom room for a mouse or mouse pad, so they use one of several different "pointing devices" that are built into the computer. (A pointing device is a mouse or other contraption that moves the cursor.)

Some portable computers use a tiny joystick-like nub located in the center of the keyboard that you lean in the direction you want the cursor to move. Others use a touch pad, in which you glide a single finger around a small area to move the cursor. Whatever pointing device you're using, they all perform the same function.

A mouse is also equipped with buttons. If you're using a Macintosh, you only have one button to contend with. If you're on a PC, you'll have two main buttons to learn - the left button and the right button. Many PCs mice also have a scroll wheel which helps the user scroll through Web pages.

The "click," which is the first mouse button function to get down, is a single tap of a button. On a Mac, it's simply called a click because there's only one button. On a PC, it's called a "left click" when you tap the left button and a "right click" when you tap the right one. If you're on a PC and someone just says, "click," they mean "left-click."

Next to learn is the "double-click," which is two quick taps of a button in succession. For the Mac, it's two taps of the only mouse button, while on the PC, a double-click refers to two taps of the left button. There is no reason to ever double-click the right button.

The double-click is where a lot of people run into trouble, so if you've never used a mouse before, this can take a little practice. For some people, the computer's mouse settings are not initially set to match their hands, but they fortunately can be adjusted (see "Chapter 10 - Accessibility").

The best way to develop all of your mouse skills is by playing Solitaire. If fact, that's why it's included with your computer - to help you get comfortable with its operation. Fortunately, using a mouse is like riding a bike. Once you get it, you've got it for life.

Again, we'll cover what the click, right-click and double-click can do for you, as well as more about mouse navigation, in chapters 6 and 7.

The box

Some refer to that large metal case sitting on your desk of floor as the system unit or console, but I prefer to call it simply "the box." And it must be real important because everything plugs into it. The box is filled with separate components that all team up to make your computer work, but for now, treat the box as one item. We'll go into greater detail about the guts of the box in "Chapter 4 - Inside the box."

For PCs, the look of the box will vary greatly, because so many different manufacturers make them. Macs come in several different styles, but Apple makes them all so the look is a bit more consistent.

If you sneak a peak at the back of the box, you'll see a spaghetti-like collection of cables (ugly, isn't it?). But again, if everything's plugging into it, this must be an important place. For now, let's stick to the front.

Playing with the knobs

If you're looking at the front of the box, you'll see the power button. You use this button to turn the computer on, but you'll typically shut the computer down through software (See Chapter 3). Shutting down properly is important because the computer always has a few things to do before it calls it quits for the day. If you simply pull the plug on it, it'll scold you the next time you start it back up.

You'll also see a button marked Reset. This is kind of a last resort button when your computer freezes up and is not responding to our keystrokes. Unfortunately, everyone will eventually have to use it.

Many PCs also have a Sleep button, which is a power-saving feature. When pressed, it'll send your computer into a comatose state that you can recover from without taking all that time to start up from scratch. This function is more useful on laptops when you're concerned with battery usage.

If you've received a real old hand-me-down PC, you might also see some rather dated things on the front that are first worth mentioning, then worth ignoring. A tiny round keyhole called the Keylock was a brilliant security idea, except that computer makers gave everyone in the world the same key. Forget about it. And if you see a Turbo button and light, forget them, too. They haven't had a use since the late '80s.

Floppy drives

Most PCs are equipped with a floppy drive. The 3-inch plastic disks that go inside these drives have been an industry standard for decades, which is amazing in a business that changes standards seemingly every five minutes.

To use the floppy drive, also called the "A drive" or "A:," insert a disk with the label facing up and the metal protector tab to the back. Use the little button to eject the disk.

Sounds like a simple little device, doesn't it? It is, but it also is a bit of a practical joker.

Some day, you'll fire up your computer and it'll stop on a black screen with a scary message sounding something like "Non-system disk error." Before you start thinking, "My files are gone! I've lost everything," don't worry. It just means that you left a floppy disk in the A drive. Pop it out, hit any key on the keyboard and you'll be starting up in no time. We'd all rest a little easier if the message just said, "You left a floppy disk in!"

Older Macs also have a floppy drive, but newer models have abandoned it in favor of Zip drives.

Zip drives

Many Macintosh computers and some newer PCs are also equipped with Zip drives, which look similar to the floppy drive but have a wider slot. They feature a slot and an eject button, but Zip disks are slightly bigger and hold much more stuff. The drive can be built into the box it or a separate unit that stands alone and connects to the box with a cable.

Insertion and ejection is similar to with a floppy drive, although you can't put a floppy disk into a ZIP drive or vice versa.

Hard drives

The plan was to stick parts of the computer that are visible here, but a brief diversion is necessary. You may use floppy and Zip drives to save stuff, but the majority of data you'll store on a computer resides on the hard drive. The hard drive lives inside the box, so you can't take a look at it unless you want to tear it open. (It's a little early for that, isn't it?)

Although hard drives vary in how much "data" (information) they can store, it will usually have plenty of room for you to operate your computer. Even though you can't see your hard drive, you know it's running when the tiny hard drive light on the front of the main box is on.

We'll cover hard drives, as well as floppy and Zip drives, more thoroughly in "Chapter 7 - Files and Folderss".

CDs, DVDs and more

Unless you're system was built prior to the mid-'90s or so, your computer will be equipped with some sort of a CD-ROM drive, which spins compact discs and reads their data using a tiny laser.

This is where we insert discs to load new programs onto our machines. The CD-ROM discs are the same size as audio compact discs, and we can even use our drive to play those music CDs. The ROM part stands for read-only memory, which means that we can't write stuff to a CD-ROM, we can only read from it. CD-ROM drives can also play music CDs.

Depending on the age of your machine or how much you paid for it, your CD-ROM drive might be more advanced. If you own a CD-R (recordable), CD-RW (rewritable) drive or DVD-R (recordable) drive, you can read and write data to specialized discs. A recordable CD can hold a decent amount of data and DVDs can hold even more. DVD drives also allow you to watch DVD movie discs on your computer, although you may prefer a 31-inch TV set and a couch to a 17-inch monitor and a desk chair.

Keep in mind that all of these more advanced drives still allow you to read the standard CD-ROMs, which is how the vast majority of programs are sold.

Regardless of which type of drive you have, operation is simple. On most PC models, it works just like an audio CD player. Press the button to open it and the tray slides out. Place the disc with the shiny side down in the circle part of the tray and press the button again to close it.

Other systems use a slot method. Just place the CD face-up into the slot (label side up) and it will take it from there. Some Macs have no button with which to eject the disc, so you have to click the CD icon on the screen, and choose Eject Disc from the Special menu.

But wait, there's more!

You'll notice some items around your desk that plug into the box.

A pair of computer speakers allows you to hear sound, just like with your stereo. We'll cover in "Chapter 15 - Music to Your Ears." The printer allows you to get a hard copy of what appears on the screen. We'll talk about printing in "Chapter 11 - Printing."

There are also a slew of devices that don't necessarily come with your computer but can be added later, such as scanners, digital cameras, CD Recorders and more. We'll talk more about that in "Chapter 28 - Upgrading."

NEXT - Chapter 4 - Inside the box