Energy exists as a fundamental concept in physics, defined as the ability to perform work, which is the application of force over distance. There is a theoretical argument that the total energy of the universe could be zero, suggesting we occupy a region with more positive energy. Energy is essentially a bookkeeping tool that helps describe and solve physical problems by quantifying the potential work an object can perform. It is intrinsically linked to mass, distance, and time, with time being meaningful only in a universe where change occurs. The existence of energy is a prerequisite for asking questions about its nature and origin.