An .ipa file is an iOS application archive file which stores an iOS app. Each .ipa file includes a binary for the ARM architecture and can only be installed on an iOS-device. Files with the .ipa extension can be uncompressed by changing the extension to .zip and unzipping.

IPA commonly refers to:

• The International Phonetic Alphabet, a system of phonetic notation
  • Its organisation, the International Phonetic Association
• India Pale Ale, a style of beer
• Isopropyl alcohol, rubbing alcohol

The International Phonetic Alphabet (unofficially—though commonly—abbreviated IPA) is an alphabetic system of phonetic notation based primarily on the Latin alphabet. It was devised by the International Phonetic Association as a standardized representation of the sounds of oral language. The IPA is used by lexicographers, foreign language students and teachers, linguists, speech-language pathologists, singers, actors, constructed language creators, and translators.

The open-mid back unrounded vowel, or low-mid back unrounded vowel, is a type of vowel sound, used in some spoken languages. Acoustically it is an open-mid back-central unrounded vowel. The symbol in the International Phonetic Alphabet that represents this sound is , graphically a rotated lowercase vee (called a turned V, though it was created as a small-capital without the crossbar), and both the symbol and the sound are commonly referred to as either a wedge, a caret, or a hat. In transcriptions for English, this symbol is commonly used for the near-open central unrounded vowel, whereas in transcriptions for Danish, it is used for the (somewhat mid-centralized) open back rounded vowel.

In linguistics, specifically phonetics and phonology, schwa ( or rarely ) (sometimes spelled shwa) refers to the mid-central vowel sound (rounded or unrounded) in the middle of the vowel chart, denoted by the IPA symbol , or another vowel sound close to that position. An example in English is the vowel sound in the 'a' of the word 'about'. Schwa in English is mainly found in unstressed positions, but in some other languages it occurs more frequently as a stressed vowel.