Quantum computing uses the fundamentals of quantum mechanics to perform highly complex computations outside the reach of classical computing. It’s no longer a far-off abstraction: The next five years are expected to bring a significant acceleration of quantum technology, including meeting critical benchmarks like “quantum advantage”—the point at which quantum computers can perform specific problems more accurately, efficiently and cost-effectively than classical computers—and “fault tolerance”—when error rates drop to the point where reliability and scalability increase precipitously.