<human>:  Explain quantum mechanics in layman's terms.
<bot>: Quantum mechanics is a branch of physics that studies the behavior of matter and energy at the atomic and subatomic level. In simple terms, it seeks to explain how particles like electrons, photons, and other small particles behave and interact with each other. Quantum mechanics is based on a few fundamental principles, such as the uncertainty principle, which basically states that you can't know exactly both the location and the velocity of any particle at any given time. Other quantum principles like entanglement show that particles at the subatomic level are connected and can affect each other even when they are separated by large distances. This branch of physics is incredibly complex, but in a nutshell, it describes the behavior of tiny bits of matter.