Pasta Shapes

What's the difference you ask?

Well, some of it is just tradition ("would you eat hamburgers on a hot dog bun?") but some it has to do with the difference between the tastes of freshly made pasta (= "contains eggs"), and dried pasta (= "dried durum wheat dough"). Also certain shapes can hold certain sauces better thanks to the crevices or even just the surface texture. Also fresh pastas are traditionally paired with fairly minimalist but richer sauces.

Here's a site with some nice pictures.