Spatial curvature is a concept used in the field of cosmology to describe the overall geometry of the universe. It refers to the curvature of the three-dimensional space that makes up the universe, and it can be described in terms of its deviation from the flat Euclidean geometry. There are three possible types of spatial curvature: positive curvature (spherical geometry), negative curvature (hyperbolic geometry), and zero curvature (flat geometry). The curvature of the universe is determined by the density of matter and energy in the universe, as described by the equations of general relativity. Understanding the spatial curvature of the universe is important for determining its overall geometry, its expansion rate, and its ultimate fate. Observations of the cosmic microwave background radiation and the large-scale structure of the universe have provided significant evidence that the universe has a nearly flat spatial curvature.