Ricci Curvature is a mathematical concept used in differential geometry to measure how much a geometric space deviates from being flat. It is derived from the more general Riemann Curvature tensor and focuses on the average curvature of a manifold in different directions. This curvature is essential in the study of Einstein's theory of general relativity, where it helps describe how matter influences the shape of space and time. A positive Ricci curvature indicates that space is curved like a sphere, while a negative value suggests a saddle-like shape.