What is a quantum computing?

Answer 1

Quantum computing utilizes nuclear spins to store and process information whereas classical computers operate using solid state electronics, notably the transistor. Quantum computing is not inherently any faster than classical computing. The difference is that quantum computing allows for parallel processing. To explain, if you asked a classical computer to perform two calculations, it would do them in sequence, returning one answer after the other. A quantum computer, when asked to do the same thing, would return both answers at once. While it performed the actual computation faster, it takes an equal amount of time in the end, because you have to figure out which answer goes to which question with the quantum computer. Certain algorithms have been developed for quantum computers (which can capitalize on purely quantum mechanical behavior such as convolution) which allow for specialized functions to be sped up. The two most common examples are directory lookups and number factoring. Because of the latter, quantum computers hold importance in the field of cryptography. Recently IBM created a quantum computer which factored 15 into 5 and 3. The technology is still in its infancy, but it is steadily moving forward.