Release types and strages

Stages of a release

A full release cycle has some defined stages while the release matures to a final one:

Alpha:
An alpha release indicates the features provided with the release have not been tested even by the developpers. This is a very early release.
Beta:
The developpers of the code feel it is functional now and a broader range of developers/users should test it now and report back any issues. There can be many iterations on the beta stage resulting in a beta 1, beta 2, etc. At least at this stage no new features should go into the release except they are absolutely mandatory.
Release Candidate:
If people feel that everything that should be taken care of has been taken care of it is time for a release candidate. For sure no new features will be added and only minor fixes are to be expected.
Final:
If a release candidate turned out to be fine it can be become the final release without changes. In any case only minor changes should be done between a release candidate and a final release.

Maintenance / Bugfix:
This type of release takes care of bugs or maintenance issues that arose after the final release. The version number might look like 2.1.1
Feature:
New features have been added which are now ready to be released. Such a release is supposed to be compatible to previous major release. The version number might be 2.1. Slide's 2.1 release is a combined bugfix and feature release.
Major:
A major release indicates something changed dramatically. It may also indicate the release is no longer compatible to the previous major release. The version number might be 3.0