en.wikipedia.org/wiki/Software_release_life_cycle
A 'software release' is the distribution (whether public or private) of an initial or upgraded version of a computer software product. Each time a software program or system is changed, the software engineers and company doing the work decide on how to distribute the program or system, or changes to that program or system. Software patches are one method of distributing the changes, as are downloads and compact discs.
Software release stages
The software release life cycle is composed of different stages that describe the stability of a piece of software and the amount of development it requires before final release. Each major version of a product usually goes through a stage when new features are added, or the alpha stage; a stage when it is being actively debugged, or the beta stage; and finally a stage when all important bugs have been removed, or the stable stage. Intermediate stages may also be recognized. The stages may be formally announced and regulated by the project's developers, but sometimes the terms are used informally to describe the state of a product. Conventionally, code names are often used by many companies for versions prior to the release of the product, though the actual product and features are rarely secret.
Beta
'Beta' is a nickname for software which has passed the alpha testing stage of development and has been released to a limited number of users for software testing before its official release. Beta testing allows the software to undergo usability testing with users who provide feedback, so that any malfunctions these users find in the software can be reported to the developers and fixed. Beta software can be unstable and could cause crashes or data loss.
A 'beta version' is the first version released outside the organization or community that develops the software, for the purpose of evaluation or real-world black/grey-box testing. The process of delivering a beta version to the users is called beta release. Beta level software generally includes all features, but may also include known issues and bugs of a less serious variety.
The users of a beta version are called beta testers. They are usually customers or prospective customers of the organization that develops the software. They receive the software for free or for a reduced price, but act as free testers.
Beta versions test the supportability of the product, the go-to-market messaging (while recruiting Beta customers), the manufacturability of the product, and the overall channel flow or channel reach.
Beta version software is likely to be useful for internal demonstrations and previews to select customers, but unstable and not yet ready for release. Some developers refer to this stage as a preview, a prototype, a technical preview (TP) or as an early access. As the second major stage in the release lifecycle, following the alpha stage, it is named after the Greek letter beta, the second letter in the Greek alphabet.
Often this stage begins when the developers announce a feature freeze on the product, indicating that no more feature requirements will be accepted for this version of the product. Only software issues, or bugs and unimplemented features will be addressed.
Developers release either a closed beta or an open beta; closed beta versions are released to a select group of individuals for a user test, while open betas are to a larger community group, usually the general public. The testers report any bugs that they found and sometimes minor features they would like to see in the final version.
en.wikipedia.org/wiki/Software_release_life_cycle