A Linux operating system where all parts of it (base system and installed software) are constantly updated with the newest version.
As opposed to a point release system, where the software stays the same for quite a while, and then everything is updated at once.

A Linux distribution that is continuously updating, instead of one that has version updates

https://en.m.wikipedia.org/wiki/Rolling_release#:~:text=Rolling release%2C also known as,which replace the previous version.