An N-sphere is a generalization of the concept of a sphere to higher dimensions. In mathematics, an N-sphere is defined as the set of points in (N+1)-dimensional space that are equidistant from a central point. For example, a 1-sphere is a circle in 2D, while a 2-sphere is the surface of a standard ball in 3D. The concept of N-spheres is important in various fields, including geometry, topology, and physics. They help in understanding complex shapes and spaces, and are often used in theories involving higher dimensions and multidimensional data analysis.