The term "quadcopter" has become a generic term for the small, highly mobile drones, initially intended for reconnaissance, which are mounted with assault rifles (technology like the Smash Dragon from Smart Shooter, with automatic target detection, lock, track, fully remote controled).

This can be mounted on commercial drones like the DJI Matrice 600 or military drones like the Thor from Elbit.

Or to describe the same kind of drones that drop explosives (this could also be a simple DJI dropping conventional grenades or IEDs).

Regarding the Smash Dragon technology:

The SMASH Dragon is an advanced robotic weaponry payload that can be mounted on different small UAVs (drones) and other unmanned aerial platforms. Featuring SMASH’s core capabilities and proprietary target acquisition, the real-time fire control algorithms direct the weapon and accurately time the shot in order to achieve a precise hit. The system is uniquely designed to lock, track, and hit unknown targets in an unknown environment, whether they be static or dynamic, day and night.

Sources:

https://www.telegraph.co.uk/global-health/terror-and-security/armed-drones-israel-hamas-war-gaza-hospitals-gunshots/

https://www.businessinsider.com/israel-drone-that-can-fire-a-sniper-rifle-while-flying-developed-2022-1

https://www.forbes.com/sites/davidhambling/2022/11/11/israels-urban-quadcopter-brings-search--attack-in-one/

https://euromedmonitor.org/en/article/6166/Gaza:-Israel-systematically-uses-quadcopters-to-kill-Palestinians-from-a-close-distance

Videos :

A quadcopter drop explosives in North Gaza

Israeli M26 Fragmentation Grenade can be seen attached to the drop mechanism from a drone. This mechanism is reportedly from a DJI Mavic drone (or similar) shown in the later part of the video that was shot down in the West Bank.

https://www.bbc.com/news/articles/c7893vpy2gqo

"We [were] operating on children who would say: 'I was lying on the ground after a bomb had dropped and this quadcopter came down and hovered over me and shot me.' "That's clearly a deliberate act and it was a persistent act - persistent targeting of civilians day after day."

Prof Mamode, former clinical lead of transplant surgery at Guy’s and St Thomas’ NHS Foundation Trust in London, said it was a "very consistent story". He added: "The bullets that the drones fire are these small cuboid pellets and I fished a number of those out of the abdomen of small children. I think the youngest I operated on was a three-year-old. "These pellets were in a way more destructive than bullets. "With the drone pellets, what I found was they would go in and they would bounce around so they would cause multiple injuries. "I had a seven-year-old boy... He had an injury to his liver, spleen, bowel, arteries, so quite extensive destruction from a single entry point. "He survived that and went out a week later."