What are the stages in Software release, what does it actually mean?

Alpha: Alpha refers to the very early release, which is typically very buggy and only released to few people internal to the organization. It is helpful, in development,

Beta: Its is the first version released out side the Organization with bugs.

Gamma or Release Candidate:
At this phase the product is also most completed and up to release with very minimum bugs. When the product reached this stage it means that, there won’t be any further change or update in the code

Gold or Release: It’s the final finished product, with only few fixes. After this stage the product will be stable for release in the market