A descriptor is an index term used to identify a record in a database. It can consist of a word, phrase, or alphanumerical term. It can describe the content of the record or be an arbitrary code. When a descriptor is descriptive, it can be an effective search parameter.

The term was coined by Calvin Mooers in 1948.

A descriptor in Symbian is a text string. There is a library of descriptor classes incorporating all the usual string manipulation methods. Descriptors come in two main types, 8 bit and 16 bit. An 8 bit descriptor stores ASCII text or binary data, a 16 bit descriptor stores Unicode text.

Information science