The Heckler & Koch UMP is a submachine gun developed and manufactured by Heckler & Koch. Heckler & Koch developed the UMP as a lighter and cheaper successor to the MP5, though both remain in production. The UMP has been adopted for use by various countries including Brazil, Canada, and the United States. A small number of UMPs chambered in .45 ACP were officially purchased by the 5th Special Forces Group of the United States Army Special Forces, with some of the weapons seeing limited service in the early years of the Iraqi insurgency, making them one of the more popular submachine guns being deployed by the U.S. military personnel in recent conflicts around the world.

The Heckler & Koch MP5 is a submachine gun developed in the 1960s by German firearms manufacturer Heckler & Koch. It uses a similar modular design to the Heckler & Koch G3, and has over 100 variants and clones, including selective fire, semi-automatic, suppressed, compact, and even marksman variants. The MP5 is one of the most widely used submachine guns in the world, having been adopted by over forty nations and numerous militaries, police forces, intelligence agencies, security organizations, paramilitaries, and non-state actors.