Augustin-Jean Fresnel was an engineer and physicist who made major contributions to the field of optics. As a result, many different things are named after him.

I am more familiar with "Fresnel" being a shading technique responsible for "rim lighting" in computer graphics, that's because this is an application of Fresnel equations, discovered by Fresnel. But in other fields, "Fresnel" can mean something else entirely, with the only thing in common being that it can be traced back to the work of Fresnel.