Quantum physics, abstract image. Three colours are shown within a subatomic particle, representing the three colour charges of quarks as described in quantum chromodynamics (QCD). Quantum mechanics is a branch of physics that describes particles in terms of quanta, discrete values rather than smooth changes. The mathematics for this involves probabilities and equations called wavefunctions. The results can be counter-intuitive when compared to normal, everyday experiences, but the theories have been confirmed by experiment and have led to major advances in disciplines such as chemistry, electronics and computing.