SIDE BY SIDE
On side-by-side handguns the barrels are placed alongside one another, as the description suggests.

Side-by-side shotguns were first created in France in the 1730s, with barrels held together by soldering. Before this, the barrels were kept in place by the stock.

The side-by-side dominated the field until the 1950s, when technology improved and better over-and-under designs appeared and now over-and-unders head the market.