Mozilla releases a new stable version of its open source Firefox web browser every four weeks. This new version introduces new features, bug and security fixes. Up until now, smaller updates were released between two major releases.
These point updates do not include new features usually but fix security issues and/or non-security issues. The releases were not predictable up until now. While you could almost be certain that a point update would be released, it was never really certain when.
This changes with the release of Firefox 151. Mozilla is switching to the same point update release rhythm that Google uses for its Chrome web browser currently.
Put simply, Mozilla plans to release a point update every week going forward. This means three Firefox point releases at the very same day of the week in-between major releases. Three point updates will follow the release of Firefox 151 and any other major browser release that follows.
The organization confirmed the change on the official Wiki (via Sören Hentzschel):
Starting with Fx151, we now have 3 weekly dot releases for Desktop and Android
Release calendar updates will be live shortly
Other than that, there is no explanation from Mozilla regarding the change yet. Considering that Google announced recently to shorten Chrome release cycles to two weeks, it is likely an attempt to stay ahead of major developments and push out fixes faster to the user base.
With AI helping Mozilla find security issues in Firefox, it is probably one reason why the organization decided to push out more updates to get these fixes on user systems as soon as possible.