The middle section, which is the largest, looks much like a standard typewriter keyboard. It contains all the letters of the alphabet, standard punctuation symbols, the numbers 0 through 9, and several special purpose keys. Most data enters a computer from this middle section of the keyboard. On some keyboards, the function keys are located across the top, just above the number keys of the middle section. Unlike the keys from the middle section, what happens when you press a function key depends on what software you are running.
Software consists of the programs that control the operation of the microcomputer.
The operation of the function keys differs from one program to the next. On the night side of the keyboard is the numeric keypad. The keys in this section are arranged like those on a calculator and are designed to speed the entry of numeric data. If data have previously been saved on a secondary storage device such as a floppy disk, then this data can serve as input to the computer. Secondary storage devices are covered more fully in Section 1.6.