Touch typists often use the lowercase letter l for the number 1 (because the l is conveniently located on the home row, and the 1 is a long reach for the left pinky). You can't do that with a computer. The computer translates each keypress into a code of 0's and 1's. The code for the letter l is different from the code for the number 1. If you save a document with the name Chapter1 and try to retrieve it by typing Chapterl (instead of Chapter1), the computer will tell you there is not such document on the disk, and you could have heart failure over your lost document before you realize what you've done.

The same is true with the capital letter O ("Oh") and the number 0 (zero). The computer will balk if you try to add a number with O in it.

The Space bar is another key on the computer keyboard that behaves differently than its typewriter counterpart. On a typewriter, a space is an area on the paper where nothing is typed. On a computer, pressing the Space bar inserts a space character. Just as 1 and l are different, so is a space character different from the space that you get when you press Right Arrow. Some applications, aware of the potential confusion, ignore extra space characters. But in other applications the word Jones and the word Jones followed by a space are as different as the words Jones and Smith.

Typing a document

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