A sitcom is usually 22 to 30 minutes long. The stories are divided into episodes that contain one or two major stories that are started and concluded within those 20-something minutes. Every 3 sentences of so, there's a joke that audiences are supposed to respond to by laughing. Laugh tracks are added so people can know when to laugh. The problem I have with this format is that I don't see how one can add one or two stories into a 22 minute show without them being unrealistic. Plus the fact that every character has a ridiculous side - there are no heroes in sitcoms!