A 1-byte character set, Single Byte Character Set (SBCS), represents each individual character in one byte. Thus, 256 different characters can be represented with such a character set.
1-byte character sets are used for letters, digits and control characters. Often double-byte character sets are constructed in such a way that they can interpret the characters from a 1-byte character set. The best known 1-byte character set is the ASCII character set.