The International Phonetic Alphabet (IPA) is a system of phonetic notation devised by linguists. It is intended to provide a standardized, accurate and unique way of representing the sounds of any spoken language, and is used, often on a day-to-day basis, by linguists, speech pathologies and therapists, foreign language teachers, lexicographers, and translators. In its unextended form (as of 2005) it has approximately 107 base symbols and 55 modifiers.

The symbols of the International Phonetic Alphabet are divided into three categories:

letters (which indicate "basic" sounds), diacritics (which further specify those sounds), and suprasegmentals (which indicate such qualities as speed, tone, and stress). These categories are then divided into smaller sections: letters are divided into vowels and consonants, and diacritics and suprasegmentals are divided according to whether they indicate articulation, phonation, tone, intonation, or stress. From time to time, symbols are added, removed, and modified by the International Phonetic Association.