Like most types of data, string values can be compared for equality or inequality or relative ordering. However, strings have some additional features to consider:
A string can be binary or nonbinary. Binary strings are used for raw data such as images, music files, or encrypted values. Nonbinary strings are used for character data such as text and are associated with a character set and collation (sorting order).
A character set determines which characters are legal in a string. Collations can be chosen according to whether you need comparisons to be case-sensitive or case-insensitive, or to use the rules of a particular language.