Development Stages

Development stages or Stages of development are main phases a product in development goes through.

Pre-Alpha
Pre-alpha is the first stages of development. Software in pre-alpha is generally not usable, and is missing key features. Pre-alpha software may be an engine without any actual game content, or a "storyboard" of sorts without final graphics, sounds, etc.

Alpha
An alpha stage is the stage of development where the software is still being actively developed and features are still being implemented. Alpha software is usually very unstable.

Beta
A beta stage is the stage of development where the software has all the features (or sometimes most of them) implemented to the product. It is used for demonstration and testing but is not actually used by the consumers. The software might have bugs and might not run properly.

Release candidate
A release candidate (RC) is the stage of development where the software has been finalized and is in the form it should be released in. A release candidate is usually released for public testing to see if there are any serious bugs or problems in the program. If there are any, they are fixed an another release candidate is released. This process continues until no serious bugs remain. When there are no bugs, the software is released to the public.

Other stages
Other stages includes Release to manufacturing (RTM), and Release to web (RTW).