Which term describes a rounded interior blend between two surfaces?

The term that describes a rounded interior blend between two surfaces is a fillet. In CAD design, a fillet is utilized to create a smooth transition between two intersecting surfaces or edges, effectively rounding off the sharp corner. This can enhance both the aesthetic appeal and the functional aspects of a design by reducing stress concentrations in mechanical components, thus preventing potential failure points.

A fillet differs from a chamfer, which is a flat or beveled edge that smooths out corners but does not create a rounded transition. A taper refers to a gradual change in thickness or width along a length, not specifically addressing the internal blending of surfaces. Edge blend is a more general term but is often associated with smoothing the edges of a face or component rather than specifically indicating the rounded interior transition characterized by a fillet. Therefore, the correct choice accurately identifies the concept of a rounded interior blend between surfaces in the context of design.