cross section

A cross section is a visual or conceptual "slice" through an object or material, revealing its internal structure as if it were cut through with a knife. Imagine slicing a loaf of bread and looking at the cut surface; that surface is the cross section. In physics and engineering, cross sections often describe the likelihood of a specific interaction, such as a particle hitting a target, measured as an effective area. It helps scientists understand the size, shape, and interaction probability of objects or particles in a way that simplifies complex three-dimensional structures into two-dimensional representations.