difference between RHEL 4 and RHEL 3
 

Whats the exact difference between RHEL 4 and RHEL 3?

Something like the difference between Fedora Core 5 and 4. Probably newer kernel, newer software, some patches/changes in init scripts or other config files...

Thanks for replying.

But i want in details. such whats are the exact changes in init file, which packages are installed etc.

I'd check out the release notes:

http://www.redhat.com/docs/manuals/e...-notes/as-x86/
https://www.redhat.com/docs/manuals/...U3-x86-en.html

That's the best you'll probably get without going through rpm -qa by yourself.

In day-to-day usage, RHEL 3,4,&5, all seem about the same. Main gotchas I've encountered are different versions of python and PHP.