i was looking for gimp for my SuSE 9.0, part of what i saw goes like:

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gimp2-2.0.1-100.SuSE.ulb.1.src.rpm
gimp2-2.0pre2-100.SuSE.ulb.1.i586.rpm
gimp2-2.0pre2-100.SuSE.ulb.1.src.rpm
gimp2-2.0pre2-100.SuSE.ulb.2.i586.rpm
gimp2-2.0pre2-100.SuSE.ulb.2.src.rpm
gimp2-2.0pre3-100.SuSE.ulb.1.i586.rpm
gimp2-2.0pre3-100.SuSE.ulb.1.src.rpm
gimp2-2.0pre3-100.SuSE.ulb.2.i586.rpm
gimp2-2.0pre3-100.SuSE.ulb.2.src.rpm
gimp2-2.0pre4-100.SuSE.ulb.1.i586.rpm
gimp2-2.0pre4-100.SuSE.ulb.1.src.rpm
gimp2-2.0rc1-100.SuSE.ulb.1.i586.rpm
gimp2-devel-1.3.23-100.SuSE.ulb.1.i586.rpm
gimp2-devel-2.0.0-100.SuSE.ulb.1.i586.rpm
gimp2-devel-2.0.1-100.SuSE.ulb.1.i586.rpm
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now i know one of them's what i want. forgive my ignorance, but, i just don't know what all those words mean: what's the difference with pre, rc, and devel? what's ulb.1 and ulb.2? what's the difference between i586 and src?

Pre and rc are about GIMP version. Before the final is released there's a number of pre and rc (release candidate) versions. When an rc is decided to be good, it's renamed to the final version. In your case gimp2-2.0.1 is the newest one (it's stable version).
I don't know what's ulb.X (probably something specific to SuSE).
.i586.rpm is binary (you just install it), when .src.rpm is a source package (you need to compile it before installing).
-devel is a collection of extra files (headers and such things) needed when you want to compile a program using that one. If you just want to use a program, you don't need it.