Quantum computing is a type of computation that harnesses the collective properties of quantum states, such as superposition, interference, and entanglement, to perform calculations. The devices that perform quantum computations are known as quantum computers. Unlike classical computers that use bits (0 or 1), quantum computers use qubits, which can exist in multiple states simultaneously. This allows them to solve specific complex problems exponentially faster than the most powerful supercomputers.
The concept of quantum computing was first proposed by physicists Paul Benioff and Richard Feynman in the early 1980s. In 1985, David Deutsch described the first universal quantum computer. A major breakthrough came in 1994 when Peter Shor developed an algorithm for factoring large integers, demonstrating the potential to break modern encryption. The first experimental quantum computers were built in the late 1990s using NMR technology.
Quantum computing has moved from theoretical physics to a competitive technological race involving governments and tech giants like IBM, Google, and Microsoft. While fully fault-tolerant quantum computers are still years away, "Noisy Intermediate-Scale Quantum" (NISQ) devices are already being used for research in chemistry, materials science, and optimization problems. The potential to revolutionize drug discovery, climate modeling, and cryptography makes it a strategic priority for many nations.