Internal test version, generally not used externally. For example: 0.4.6-alpha.0.
The public beta version fixes a large number of serious defects and problems based on the alpha version, and can be released and used externally. For example: 0.4.6-beta.1.
There is basically no problem with the public candidate version, and it can be released and used externally. Is the version before the official version is released. For example: 0.4.6-rc.8.
Officially released version. For example: 0.4.6.