Your PC (Personal Computer) is asystem, consisting of many components. Some of those components, like WindowsXP, and all your other programs, are software. The stuff you can actually seeand touch, and would likely break if you threw it out a fifth-story window, ishardware.
Not everybody has exactly the same hardware. But those of you who have adesktop system, like the example shown in Figure 1, probably have most of thecomponents shown in that same figure. Those of you with notebook computersprobably have most of the same components. Only in your case the components areall integrated into a single book-sized portable unit.
Figure 1
The system unit is the actual computer; everything else iscalled a peripheral device.Your computer's system unit probably has at least one floppy disk drive, andone CD or DVD drive, into which you can insert floppy disks and CDs. There'sanother disk drive, called the hard disk inside the system unit, as shown inFigure 2. You can't remove that disk, or even see it. But it's there. Andeverything that's currently "in your computer" is actually stored onthat hard disk. (We know this because there is no place else inside thecomputer where you can store information!).
Figure 2
The floppy drive and CD drive are oftenreferred to as drives withremovable media or removabledrives for short, because you can remove whatever disk is currentlyin the drive, and replace it with another. Your computer's hard disk can storeas much information as tens of thousands of floppy disks, so don't worry aboutrunning out of space on your hard disk any time soon. As a rule, you want tostore everything you create or download on your hard disk. Use the floppy disksand CDs to send copies of files through the mail, or to make backup copies ofimportant items.
Random Access Memory (RAM)
There's too much "stuff" onyour computer's hard disk to use it all at the same time. During the averagesession sitting at the computer, you'll probably use only a small amount of allthat's available. The stuff you're working with at any given moment is storedin random access memory (often abbreviated RAM, and often called simply"memory"). The advantage using RAM to store whatever you're workingon at the moment is that RAM is very fast. Much faster than any disk. For you,"fast" translates to less time waiting and more time beingproductive.
So if RAM is so fast, why not put everything in it? Why have a hard disk atall? The answer to that lies in the fact that RAM is volatile. As soon as thecomputer is shut off, whether intentionally or by an accidental power outage,every thing in RAM disappears, just as quickly as a light bulb goes out whenthe plug is pulled. So you don't want to rely on RAM to hold everything. Adisk, on the other hand, holds its information whether the power is on or off.
The Hard Disk
All of the information that's "inyour computer", so to speak, is stored on your computer's hard disk. You never see thatactual hard disk because it's sealed inside a special housing and needs to staythat way. Unlike RAM, which is volatile, the hard disk can hold informationforever -- with or without electricity. Most modern hard disks have tens ofbillions of bytes ofstorage space on them. Which, in English, means that you can create, save, anddownload files for months or years without using up all the storage space itprovides.
In the unlikely event that you domanage to fill up your hard disk, Windows will start showing a little messageon the screen that reads "You are running low on disk space" well inadvance of any problems. In fact, if that message appears, it won't untilyou're down to about 800 MB of free space. And 800 MB of empty space is equalto about 600 blank floppy disks. That's still plenty of room!
Obviously you know how to use yourmouse, since you must have used it to get here. But let's take a look at thefacts and buzzwords anyway. Your mouse probably has at least two buttons on it.The button on the left is called the primary mouse button, the button on the right is called the secondary mouse button or justthe right mouse button.I'll just refer to them as the left and right mouse buttons. Many mice have asmall wheel between the two mouse buttons, as illustrated in Figure 3.
Figure 3
The idea is to restyour hand comfortably on the mouse, with your index finger touching (but notpressing on) the left mouse button. Then, as you move the mouse, the mouse pointer (the little arrowon the screen) moves in the same direction. When moving the mouse, try to keepthe buttons aimed toward the monitor -- don't "twist" the mouse asthat just makes it all the harder to control the position of the mouse pointer.
If you find yourself reaching too farto get the mouse pointer where you want it to be on the screen, just pick upthe mouse, move it to where it's comfortable to hold it, and place it back downon the mousepad or desk. The buzzwords that describe how you use the mouse areas follows:
- Point: To point to an item means to move the mouse pointer so that it's touching the item.
- Click: Point to the item, then tap (press and release) the left mouse button.
- Double-click: Point to the item, and tap the left mouse button twice in rapid succession - click-click as fast as you can.
- Right-click: Point to the item, then tap the mouse button on the right.
- Drag: Point to an item, then hold down the left mouse button as you move the mouse. To drop the item, release the left mouse button.
- Right-drag: Point to an item, then hold down the right mouse button as you move the mouse. To drop the item, release the right mouse button.
The Keyboard
Like the mouse, the keyboard is a meansof interacting with your computer. You really only need to use the keyboardwhen you're typing text. Most of the keys on the keyboard are laid out like thekeys on a typewriter. But there are some special keys like Esc (Escape), Ctrl(Control), and Alt (Alternate). There are also some keys across the top of thekeyboard labeled F1, F2, F3, and so forth. Those are called the function keys, and the exact rolethey play depends on which program you happen to be using at the moment.
Most keyboards also have a numeric keypad with the keyslaid out like the keys on a typical adding machine. If you're accustomed tousing an adding machine, you might want to use the numeric keypad, rather thanthe numbers across the top of the keyboard, to type numbers. It doesn't reallymatter which keys you use. The numeric keypad is just there as a convenience topeople who are accustomed to adding machines.
Figure 4
Most keyboards also contain a set of navigation keys. You can use thenavigation keys to move around around through text on the screen. Thenavigation keys won't move the mouse pointer. Only the mouse moves the mousepointer.
On smaller keyboards where space islimited, such as on a notebook computer, the navigation keys and numeric keypadmight be one in the same. There will be a Num Lock key on the keypad. When theNum Lock key is "on", the numeric keypad keys type numbers. When theNum Lock key is "off", the navigation keys come into play. The NumLock key acts as a toggle. Which is to say, when you tap it, it switches to theopposite state. For example, if Num Lock is on, tapping that key turns it off.If Num Lock is off, tapping that key turns Num Lock on.
Combination Keystrokes (Shortcutkeys)
Those mysterious Ctrl and Alt keys areoften used in combination with other keys to perform some task. We often referto these combination keystrokes as shortcut keys, because they provide analternative to using the mouse to select menu options in programs. Shortcutkeys are always expressed as:
key1+key2
where the idea is to hold down key1, tap key2, then release key1. For example, to press Ctrl+Eschold down the Ctrl key (usually with your pinkie), tap the Esc key, thenrelease the Ctrl key. To press Alt+F you hold down the Alt key, tap the letterF, then release the Alt key.