Anapana(sati) is a specific kind of onepointedness exercise on following the breath; there are many, many more. (Literally, āna is inbreath, āpāna is outbreath,

Anapana(sati) is a specific kind of onepointedness exercise on following the breath; there are many, many more. (Literally, āna is inbreath, āpāna is outbreath, sati is 'remembering of'). What the (Goenka) Vipassana tradition teaches as Anapanasati is an overly specific extrapolated reading not supported by the Anapanasati Sutta itself. Scholar/monk Bhikku Analayo has published on this topic extensively. Many others have actually. The sutta itself is so vague that you can interpret it in any number of ways. Thai Forest Bhikku Buddhadasa even managed to fit Pranayama-like active breathing into his teaching of this sutta.