What exactly is a sitcom? In particular: what distinguishes sitcoms among the (presumably) broader category of comedy series?
It's easy enough to give classical examples of sitcoms. They tend to have several common features: usually there is a recurring set of characters who are put in comical situations, often there is a laugh track, usually it's pure comedy (as opposed to comedy + action, or comedy + fantasy, etc.), usually plot progression is relatively slow.
I'm curious which features are essential for a series to be considered a sitcom. This question arose from an attempt to figure out if The Good Place is a sitcom; it seems to be something of an edge case. However, I'm more interested in a general answer.