A character set (sometimes called a code page) represents characters on a computer. There are many character sets in use today.
Because different languages need different characters, character sets are often designed to support particular languages. Many different character sets may support the same language.
When computers or computer applications exchange character data, they must use the same character set or convert the data from one character set to the other during the transfer process. Otherwise, the data may have a different meaning after the transfer. The same is true for numeric data, but there are fewer ways to represent numbers, so it is a lesser problem.
A character set has characters it supports, a character string representation, and an implied collation based on this representation.