One spin for one revolution
The Moon completes one spin against distant stars during each orbit of Earth, keeping approximately the same hemisphere toward us. Without rotation, different lunar longitudes would face Earth during an orbit.
The comparison uses rotation and revolution against the stellar background. The phase cycle also depends on Earth’s motion around the Sun and is longer, so the interval between full moons is not the lunar spin period.
Delayed deformation and energy dissipation
Differential terrestrial gravity deforms the Moon. Material response need not align instantly with the forcing direction, allowing a torque to change rotation while some mechanical energy is dissipated as heat.
NASA illustrates synchronization through the slowing of an initially faster-spinning Moon. Evolution depends on shape, material response, orbit and other bodies, so the lunar path and timescale are not universal templates.
Synchronization leaves continuing evolution and daylight
The lunar far side receives sunlight and the near side experiences night. Far side describes Earth-facing geometry, while phases describe changing illumination, neither implying absent rotation.
The Moon’s locking does not mean Earth is already locked to it. Earth still rotates daily and tidal exchange continues to evolve spin and orbit. Pluto and Charon provide a mutually locked example, distinguishing one-sided from mutual synchronization.