Zero-point energy refers to the lowest possible energy state that a physical system can possess, even at absolute zero temperature. It is a fundamental concept in quantum mechanics and is associated with the inherent uncertainty and fluctuations present in the quantum realm.
 
According to the principles of quantum mechanics, particles such as atoms and subatomic particles do not exist in definite positions with precise energies. Instead, they exhibit a degree of inherent uncertainty known as the Heisenberg uncertainty principle.
 
This uncertainty implies that even in the lowest energy state, called the ground state, particles continue to exhibit small, random fluctuations in their position and energy.