The term "incidence" has several meanings, depending on its context.
In general terms, incidence refers to the occurrence or happening of an event or situation. It can also refer to the rate at which something happens or occurs, such as the number of new cases of a disease in a given period of time.
In mathematics and physics, "incidence" specifically refers to the intersection points between two objects or figures, such as lines, curves, or surfaces. In this context, it can also refer to the angle at which these intersecting lines meet.
Additionally, incidence can be used in economics to describe the taxation of income or goods, where "incidence" refers to who ultimately bears the burden of the tax - either the consumer or the producer.