Depending on the recording target, sometimes you have to use the 'DirectX/OpenGL window' mode; sometimes you have to use the 'Rectangle on a screen' mode.
[DirectX/OpenGL window] mode offers a better quality recording than the [Rectangle on a screen] mode.
If possible, it is better to use [DirectX/OpenGL window] mode. » See more
[Rectangle on a screen] allows you to record everything on your computer screen. » See more
[DirectX/OpenGL window] recording
[DirectX/OpenGL window] mode is for recording games or streaming videos.
Various 2D/3D games: Skyrim, Battlefield 3, Call of Duty (MW3), WOW, StarCraft 2, Minecraft, RuneScape, Aion, MapleStory, Second Life, Age of Conan, EverQuest, etc
Streaming video play program: iTunes, Windows Media Player, Real, GOM