The Riemann sphere is a mathematical concept that represents the extended complex plane. It visualizes complex numbers as points on a sphere, where each point on the sphere corresponds to a unique complex number. The north pole of the sphere typically represents infinity, allowing for a more comprehensive understanding of complex functions. This model is named after the mathematician Bernhard Riemann, who contributed significantly to complex analysis. The Riemann sphere simplifies the study of complex functions by providing a geometric perspective, making it easier to analyze properties like continuity and limits in a more intuitive way.