Green Screen Video
These are usually "TV style" sit down interviews in a carefully lit, controlled environment or a set with excellent audio quality.
They can be any length and are great for Q&A and in-depth interviews, where the interviewer is often mic'd and talks to and asks questions of the interviewee. To make the video more interesting to watch, multiple camera angles, usually two are used.
The difference of course between green screen videos and regular videos is that the green background can be replaced digitally with the background of your choosing! or multiple backgrounds to give the video multiple uses!
This sample clip is a minute long: