In Red Hat Linux 7.2, Red Hat provides its first officially supported journaling file system: ext3. The ext3 file system is a set of incremental enhancements to the robust ext2 file system that provide several advantages. This paper summarizes some of those advantages (first in general terms and then more specifically), explains what Red Hat has done to test the ext3 file system, and (for advanced users only) touches on tuning.

Source: www.redhat.com/resourcelibrary/whitepapers/ext3

Thanks, but I was replying to someone else who has asked about the
advantages of ext3 over ext3 using the very same URL that you just
noted.

The ext3 filesystem uses the same disk format that ext2, but the main difference is that ext3 adds journaling capabilities. You are going to find it in kernels 2.4.16+
Journaling : offers metadata, ordered data writes, full metadata + data.