What is the best video capture software for Linux operating systems?

Linux

Thank you @sethsmitchells for a detailed answer but I would love to highlight a few points which you will find relevant.

In the case of a video capture application in Linux, it should be considered in terms of the requirements, in the case of simple recording requirements you have some options to choose and in the case of a fully equipped screen recorder you have very few options to choose. OBS Studio is the top choice to most users as it allows screen and window capture, audio mixing, multiple sources, and recording and live streaming, all at no cost and open source. SimpleScreenRecorder or Kazam are also lighter, though still good, options, should you simply want to record your desktop without the complexity. Others use them together with ScreenRec when they need a fast method of capturing screenshots or short captures with easy shareable links, and the native tools when they need to do more serious work and ScreenRec when they need to capture a quick grab-and-go shot.