A more thorough explanation:

A Jepson claim is a type of patent claim that describes an improvement to an existing invention. It starts with a statement about the current state of the art, followed by the phrase "the improvement comprising" and a description of the claimed patentable improvement. The name comes from a case in which this type of claim was first approved and sanctioned by the Commissioner of Patents.

Let's say that there is an existing patent for a car that has four wheels. An inventor comes up with an improvement to the car that makes it more fuel-efficient. They could file a Jepson claim that starts with a statement about the existing car with four wheels and then describes the improvement of making it more fuel-efficient.