Airsoft is an informal term in reference to BB guns that use plastic BB's larger than the common BB's sold in local sporting goods stores which are 6mm in circumference. The difference/advantage is that with Airsoft, players can safely train/simulate/play with weapons that appear identical to their real counterparts, but without the fear of serious injury. These toy guns both feel, look, and act like the real thing. They are both the same weight and size as the real things. The tops of these guns cock back (called blow back) when fired, like the guns in the arcade game Point Blanc. Here is a small clip of a G17 and a USP. They also load and shoot small paint balls in addition to regular plastic pellets.