What does i386, 1586 mean
 

I am new to linux i was wondering what does the terms i386 i586 i 686 mean. when ever using some rpm they have different rpms . I am using mandrake linux 9.1 on amd athlon 1700+

search the forums, has been asked before.

means 386 or above and i586 means pentium or above

For an athlon, it makes no difference whether you use i386, i486, i586 or i686. All will work just fine. (there might be tiny differences in performance, but your CPU will support them all).

So, if you're looking for RPMs, if you get any of those, they should work. Sometimes you may even see RPMs tailored specifically for the athlon - if they're called whatever-program-athlon.rpm, that will work on your CPU as well.

just curosity . does a pentium support the i386 too or a 486 can support i686

A Pentium will work with anything up to i586. A 486 can work with anything up to i486. It's all kind of confusing, but I'd suggest just sticking with i386 since that's what you see pretty much everywhere, or i586 if you're running on newer CPUs.