The Stress-Energy Tensor is a mathematical object used in physics to describe the distribution of energy, momentum, and stress in a given region of space. It encapsulates how matter and energy influence the curvature of spacetime, which is a key concept in General Relativity. The tensor provides a comprehensive way to represent various physical quantities, such as pressure and energy density, in a unified framework. In essence, the Stress-Energy Tensor helps scientists understand how different forms of energy and momentum interact with gravitational fields. It plays a crucial role in formulating the equations that govern the dynamics of Einstein's field equations, linking the geometry of spacetime to the physical content within it.