French knickers hang from the hips and cover most of the buttocks, with just a little flesh peeping out from the bottom of the lingerie, which men find irresistible. They come in all different kinds of fabric, but silk or satin french knickers are popular choices.
Some ladies like to wear french knickers, others prefer thongs. You don’t need to choose one over the other, it’s always nicer to have a selection of everything, but this article on Thongs vs French Knickers is a good guide to all things knicker-related!