Quantum theory focuses on the behavior of subatomic particles, emphasizing probabilistic and discontinuous interactions, while relativity addresses the dynamics of large-scale objects, presenting a smooth and deterministic framework. Relativity is divided into special relativity, which explores the relationship between time and space, and general relativity, which deals with universal gravitation and kinetic motion. Both theories are essential in physics, providing models that describe different aspects of the universe rather than offering direct explanations. The consensus among physicists is that both theories are valuable, depending on the context of the phenomena being studied. Understanding these theories requires extensive reading, even at a layman's level, due to their complexity.