Comic Relief

IF I'M NOT MISTAKEN, I THINK THAT DATA WAS THE COMIC RELIEF ON THE SHOW. 

What is the comic relief?
Comic relief usually means a releasing of emotional or other tension. Comic relief often takes the form of a bumbling, wisecracking sidekick of the hero or villain in a work of fiction. A sidekick used for comic relief will usually comment on the absurdity of the hero's situation and make comments that would be inappropriate for a character who is to be taken seriously.

2-Why it is often used in horrors films? 
Because it gives a releasing time during tense moments. 

3- Do you remember laughing in horrors films? Can you think of an example?
Yes,I remember laughing in horrors films. I can think an example: Scary movie.