Spacetime is a mathematical and physical concept that unifies the three dimensions of space with the single dimension of time into a four-dimensional continuum. This framework describes the geometry of the universe, treating time not as an independent variable but as a dynamic dimension intertwined with spatial coordinates. The fundamental principles associated with spacetime dictate that the presence of mass and energy causes a curvature in this fabric. This curvature, in turn, determines the paths that objects take, meaning that gravitational interactions are understood not as a force acting across space, but as the movement of objects following the curves of spacetime geometry.