Quantum computing utilizes a fundamental concept known as quantum superposition, which allows quantum bits, or qubits, to exist in a superposition of states. Unlike classical bits that can represent either a 0 or a 1, qubits can be in a state that is a combination of both 0 and 1 simultaneously.
In classical computing, information is processed using bits that can be in either a 0 or a 1 state. However, in quantum computing, qubits can exist in a state known as a quantum superposition, where they represent a weighted combination of 0 and 1. This superposition enables quantum computers to perform certain calculations in parallel and potentially provide exponential speedup for specific problems.
The superposition of qubits allows them to represent multiple states simultaneously. For example, a two-qubit system can be in a superposition of four states: 00, 01, 10, and 11, each with a corresponding probability amplitude. As more qubits are added to a quantum system, the number of possible states and their associated probability amplitudes grows exponentially.
When a measurement is made on a qubit, it collapses into one of its possible states with a certain probability based on its amplitudes. The result obtained from a measurement is a classical bit, either 0 or 1, depending on the collapsed state of the qubit. The process of measuring qubits introduces randomness and destroys the quantum superposition.
In summary, while classical computing is based on bits representing 0 or 1, quantum computing utilizes qubits that can exist in a superposition of 0 and 1 states, allowing for more complex and parallel computations.