It's easy to videotape a person talking. As a result, many videos stop there. The best videos also include a variety of graphical elements to hold the person's interest. The use of 3D animation, special visual effects, interesting backgrounds, scene changes, a well-written script, great music, nice lighting and effective transitions from scene to scene are all techniques to hold the viewer's interest.
Professional video producers often use what is called "b-roll." B-roll refers to cutaway shots that can be used as the visual part of an interview or narration, which "overlays" the interviewer's audio portion. The cameras may zoom in on an object that a person is talking about, rather than the interviewees themselves.
B-roll footage is used to make a video more interesting, but it can also be used to hide an interviewer's verbal or physical tics. In the case of b-roll, the audio interview (or voice-over) is separate from the video (visual aspect). The producers are free to cut out the sniffs, coughs and so forth. It also is used to cut out an irrelevant part of a sentence in an interview. It's easy to make a video, but it is a truly an art form to make an exceptional video.