UAVs (Unmanned Aerial Vehicles) have a long history of development dating back to Nikolas Tesla in 1915. Concerned about losing pilots over hostile territory, the United States and Israel pioneered much of the UAV technology we see today.
Nowadays, UAVs are controlled from a remote location (even thousands of kilometers away), while others fly autonomously based on pre-programmed flight plans. They are optimal for surveillance and reconnaissance but have other purposes as well, like transport, search and rescue and even commercial uses such as firefighting.
The drone featured in the video is the Skylark I-LE, specially modified by the IDF and chosen for its lightness and extraordinary stealth. Click to read more about the Skylark I-LE.