ASCII

Decades ago, the American Standard Code for Information Interchange (ASCII) was developed to define all the letters, numerals, and special characters that a computer would use as its language. All these symbols were represented using seven bits. This allowed for 128 symbols, which is enough for all the lower and upper case letters in the Latin alphabet, the 10 digits, and an assortment of punctuation symbols.

Most computers extend the ASCII character set to use the full range of 256 characters available in a byte. The first 128 decimal numbers are assigned to letters, numbers, punctuation marks, and the most common special characters. The Extended ASCII Character Set represents additional special, mathematical, graphic, and foreign characters. The first 32 characters of the ASCII table are non-printing characters and are used for control purposes only. The first printable character is the space (byte 00100000).

As an example, ASCII defines the character "S" to be represented by 01010011 in binary. When you hold down the shift key and strike the "s" key, the series of electrical pulses "01010011" are stored in your computer. This combination of eight bits is called a byte. The processor in your computer can use these electrical pulses, or computer language.