'Quantum computing' involves computing based on the principles of quantum mechanics, contrasting with classical computing. Quantum computers utilize quantum bits or qubits, which can exist in multiple states simultaneously, enabling them to perform complex calculations at unprecedented speeds. This allows quantum computers to solve problems that would be infeasible for classical computers, such as factoring large numbers and simulating molecular structures. The potential applications span various fields, including cryptography, optimization, and drug discovery, promising revolutionary advancements in technology.