Beta can stand for:
- Β or β the 2nd letter of the Greek alphabet. See Beta (letter). Beta should not be confused with a similar-looking but unrelated letter in German language orthography, ß, which denotes a voiceless "s" sound.
- From its position in the Greek alphabet, beta often stands for the second in a series; e.g., β Centauri for the second brightest star in constellation Centaurus.
- The plant genus Beta, the beets, in the family Chenopodiaceae (or, in more recent classifications, Amaranthaceae).
- The Betta splendens, commonly known as the "Siamese fighting fish".
- A Russian time signal service, Beta (time signal)
- Beta is the traditional name of the second Magic: The Gathering card set.
When derived from the Greek letter, Beta can have any of the following meanings:
- The International Phonetic Alphabet symbol for the voiced bilabial fricative
- In software development, a beta version of a product is one that is still in development but is published for testing purpose. See development stage.
- BETA is an object-oriented programming language.
- The Beta programming language was used with the early cryptanalytic computer Harvest.
- In video tape technology, Beta is an abbreviation for Betamax.
- In climbing, a slang term for information about the moves needed to do a specific climb: see on-sight climbing.
- Beta coefficient. In investment, beta is a measure of volatility or level of risk against a benchmark, which can be the market or industry as a whole. It is calculated over a period of months. A value greater than one indicates that the object tends to change at a greater magnitude, whatever the direction.
- In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted.
- The beta distribution is a probability distribution defined in terms of the beta function.
- In visual psychology, beta movement is a perceptual illusion in which a sequence of still images appears to be moving.
- In electrical engineering and electronics, the Greek letter β is often used to represent the DC common emitter current gain of a bipolar junction transistor.
- In electrical engineering and electromagnetic theory, the Greek letter β is often used to represent the phase constant of a plane electromagnetic wave.
- Beta is an Indian film from 1992 starring Madhuri Dixit;
- Beta is an Italian motorcycle manufacturer.
- Beta is information about a climb. It has also permiated into most mountain culture as slang for "info".