I haven't seen the term "swing" used with derailleurs, but there is a common distinction between bottom pull and top pull.

The bottom pull derailleurs route the shift cable along the downtube of the bike, and either above or below the bottom bracket, then up to the derailleur.

Top pull derailleurs will route the shift cable along the top tube, then down the seat tube, and pull the derailleur from the top side.

A third type of bottom pull derailleurs is primarily seen in vintage bikes and requires a cable stop to be integrated with the derailleur, and may require either vintage parts, or a clamp-on cable stop to be added/changed.