# Intro to Quantum Computation and Communication

An analogy: Newtonian physics is an approximation to Einsteinian physics (general relativity). Classical physics is an approximation to quantum mechanics. Classical information is an approximation to quantum information. In each case, the approximation excludes important details but serves well for many purposes. In each case, removing the approximation requires deeper understanding and harder math, but results in a truer picture of Nature and may enable new technologies.