Characteristics
As opposed to stand up comedy and sketch comedy, a situation comedy has a storyline and ongoing characters in, essentially, a comedic drama. The situation is usually that of a family, workplace, or a group of friends through comedic sequences.
Traditionally comedy sketches were presented within a variety show and mixed with musical performances, as in vaudeville. The emerging mass medium of radio allowed audiences to regularly return to programs, so programs could feature the same characters and situations each episode and expect audiences to be familiar with them.
Sitcom humor is often character driven and by its nature running gags evolve during a series. Often the status quo of the situation is maintained from episode to episode. An episode may feature a disruption to the usual situation and the character interactions, but this will usually be settled by the episode's end and the situation returned to how it was prior to the disruption. These episodes are then linked by the overarching storyline, driving the show forward.
Read more about this topic: Sitcom