Nightly is the build generated each night from the latest trunk code. After 6 weeks, nightly becomes aurora, which is more stable (not updated each night). Then

Nightly is the build generated each night from the latest trunk code. After 6 weeks, nightly becomes aurora, which is more stable (not updated each night). Then after 6 weeks, it becomes beta and is tested by a wide audience. After 6 more weeks, it is released as the current stable version.