Differential geometry is a branch of mathematics that deals with the study of curves, surfaces, and higher-dimensional manifolds using the techniques of calculus and linear algebra. It investigates the geometric properties of these objects, such as curvature, angle measures, and distances, and how they can be described and analyzed using differential equations. Differential geometry has applications in various fields such as physics, engineering, computer science, and even art and design. It plays a crucial role in understanding the geometry of space-time in general relativity and in the development of algorithms for computer graphics and computer-aided design.