Specifically, women's underwear. They rise a little higher than conventional panties, and the legs are a little longer (but not more than about an inch either way). Some variants of boyshorts even have a Y-front, much like guys' briefs, hence the name of boyshorts. Almost a tradeoff between boxer shorts and panties/briefs, though more form-fitting than boxers. Their popularity has surged lately, for several reasons: a) they provide more coverage, and can be worn underneath a dress with a little more confidence; b) they generally don't show any VPL; c) they are comfortable - apparently a damn sight more comfortable than a G-string, at any rate; d) they are hot. Guys and gals both love them, mainly because girls tend to look hot in pretty much any guys' clothing. No clue why. I blame hormones.