This is used by paid features:
There are two levels of configuration. On application level you can configure how the repository type is detected based on fetch URI. Glob patterns always take precedence over auto-detect.
Globs are matched against entire fetch URI, so they should usually start and end with *.
For example: if GitHub is available under ghe.com host name then glob should be *ghe.com*.

On the project level you can see which type was detected based on settings on app level.
