[Thedae2k]

The difference is that products.tpl displays products in a straight down listing and the products_t.tpl uses multicolum boxes to display products. both can be competely modified to look and function as you need.

The search and category function returns results using one of those two templates.

You should start with using the Webmaster Mode provided and find the correct template(.tpl file) and edit the layout for your taste. You can also choose in the Apppearance Section under Displaying products of the General Settings which format you want to use.