There are four Firefox update channels. Normal user should always install the current Firefox 45.0.1 release. The other update channels are for testers. The beta version is the version that will become the next Firefox release (46.0). The beta versions is updated twice a week. There are two other alpha versions, Developer Edition 47.0 alpha2 and Nightly 48.0 alpha 1 ,that are more unstable and that receive an update each day. You can only switch the update channel by installing a full Firefox version. You can find the full version of the current Firefox release (45.0.1) in all languages and all operating systems here: *https://www.mozilla.org/en-US/firefox/all/