A character is any letter, number, space, punctuation mark, or symbol that can be typed on a computer. The word "computer," for example, consists of eight characters. The phrase "Hi there." takes up nine characters. Each character requires one byte of space, so "computer" takes up 8 bytes. The list of characters that can be typed is defined by the ASCII and extended ASCII set. Some of the symbols available are pretty strange and may even make you say, "That's quite a character!"