Many distributions have what is called a "fixed" release. While they may have several names for it, it is simply a fixed release where several things happen...

First, new packages are uploaded to a new build of the current system, which is released on a fixed date. For example, programs for Ubuntu's next release, Hardy Heron, includes new applications not found in Ubuntu 7.10, Gutsy Gibbon.

The next release type is called a "rolling" release. Possibly the best example of this type of release is PCLinuxOS. This release cycle has no real fixed release, but instead new applications are simply uploaded to the system's repositories.

After using several systems that use each, I have come to a better understanding of their actual value. I have learned there are pros and cons to each:

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