The behavior of qubits, which are the fundamental units of quantum information, can indeed be quite different from classical bits. While it is true that when a qubit is measured, it collapses into either a state representing a classical bit 0 or a classical bit 1, the key distinction lies in the superposition and entanglement properties of qubits.
Superposition allows a qubit to exist in a combination of both 0 and 1 states simultaneously. In other words, before a qubit is measured, it can be in a state that represents a probability distribution over 0 and 1. This superposition is what provides qubits with the potential for more possibilities than classical bits. For example, a qubit can be in a state that represents a 50% probability of being measured as 0 and a 50% probability of being measured as 1. This is different from a classical bit, which can only be definitively in one state (0 or 1) at a given time.
Furthermore, qubits can also exhibit entanglement, which is a phenomenon where the states of multiple qubits become intertwined and correlated with each other. When qubits are entangled, the measurement of one qubit can instantaneously affect the state of another qubit, regardless of the physical distance between them. This property enables quantum computers to perform certain computations more efficiently than classical computers.
So, while the measurement of a qubit ultimately yields a classical bit, the ability of qubits to exist in superposition and entangled states grants them a greater range of possibilities and computational power than classical bits. It is the manipulation and exploitation of these quantum properties that underlie the power of quantum computing.