Quantum Computation

Rather than store information as 0s or 1s as conventional computers do, a quantum computer uses qubits – which can be a 1 or a 0 or both at the same time. This “quantum superposition”, along with the quantum effects of entanglement and quantum tunnelling, enable quantum computers to consider and manipulate all combinations of bits simultaneously, making quantum computation powerful and fast.

How D-Wave Systems Work
Quantum computing uses an entirely different approach than classical computing. A useful analogy is to think of a landscape with mountains and valleys.

Solving optimization problems can be thought of as trying to find the lowest point on this landscape. Every possible solution is mapped to coordinates on the landscape, and the altitude of the landscape is the “energy’” or “cost” of the solution at that point. The aim is to find the lowest point on the map and read the coordinates, as this gives the lowest energy, or optimal solution to the problem.