Classical computers have a memory circuit operating on “bits.” A bit is a binary piece of information, valuing 0 or 1. Since they are binary, bits are slow, and multiple bits are required to complete the simplest equations on a classical computer.
Quantum computers operate on quantum bits, or “qubits.” A qubit is a basic unit of quantum information; unlike bits, qubits can exist in multiple states. A qubit can be in a 1, a 0 or a superposition of both, called a quantum state — this ability is fundamental to the function of quantum computers. Because qubits can exist beyond a binary state, they complete equations much quicker than bits.