Comparing Mac and Windows Keyboards
Apple’s keyboard layouts look very much like standard Windows keyboards. The biggest difference is in the two keys on either side of the spacebar. On a PC, the keys closest to the spacebar are labeled Alt; the next one over has a Windows logo. On a Mac, the keys closest to the spacebar have an icon (Command) that looks like a four-bladed propeller or electric fan. These Command keys both have the same function. The next one over is the Option key.
The Command key is used in almost all keyboard shortcuts. It’s one of the most important things to know about the Mac.
Another key that may not be familiar to PC users is at the upper-right on Apple keyboards. It’s the eject button for the optical drive (that reads and writes CDs and DVDs). You see the same symbol on the eject button on home audio devices. Continuing to the left on stand-alone keyboards, you find a key with a speaker symbol, which turns the system sound on and off. It’s a mute button, in effect. It is followed by two keys that raise and lower the volume.
The keyboards built into Apple laptops and Apple's wireless keyboard have fewer keys than Apple's wired stand-alone keyboard. No separate numeric keypad is available. You can use a group of keys on the right side as a keypad by activating the Num Lock function (press Control+F6). On many Mac keyboards, the sound-control keys, screen-brightness, and other controls are on the function keys.
The large key at the right end of the numeral row on PC keyboards is labeled Backspace and deletes the character to the left of the insertion point. Long ago, Apple decided to label this key Delete, because that is what it really does. The problem is that PC keyboards have another, regular-sized Delete key in the group above, or sometimes next to, the arrow keys. This Delete key deletes the character to the right of the insertion point. Apple first omitted this key. Later, when Apple switched to connecting by USB for its stand-alone keyboards, the second delete key came back, labeled del or delete. It also has a standard delete symbol on it which looks like a boxy arrow pointing right with an x in it. The big Delete key doesn’t have a symbol on it, though one exists, and it has the same boxy arrow pointing left. The Apple laptops don’t have a second delete key, but you get the right delete function by holding down the function key (fn) when you press the Delete button.