Geometry is a branch of mathematics that deals with the study of shapes, sizes, properties, and spatial relationships of objects in space. It encompasses various concepts such as points, lines, angles, surfaces, and solids. Geometry is used to understand and describe the properties of both two-dimensional and three-dimensional shapes, as well as their interactions and transformations. It has practical applications in fields like architecture, engineering, physics, and computer graphics, and plays a fundamental role in understanding the structure of the physical world.