The letter "æ" is a character known as "ash," used in several languages, including Old English and Danish. It represents a vowel sound that is a blend of "a" and "e." In modern usage, it appears in some words and names, particularly in Scandinavian languages. In English, "æ" is not commonly used, but it can be found in some borrowed words, such as "encyclopædia." The character is also used in phonetics to denote specific vowel sounds, helping linguists describe pronunciation more accurately.