Quantum annealing is a heuristic quantum algorithm or computational method designed for finding approximate or exact solutions to optimization problems. This approach navigates complex energy landscapes by adiabatically evolving a quantum system from a simple initial ground state to a final ground state encoding the solution, leveraging quantum mechanical phenomena such as tunneling and superposition. Its significance lies in its application as a potential hardware-implementable strategy for tackling computationally intractable problems, particularly those expressible as quadratic unconstrained binary optimization (QUBO).