Hybrid Autofocus
A system combining phase detection for speed and direction with contrast detection for final precision.
In depth
Phase detection gets the lens close in a single decisive movement; contrast detection then refines the last fraction, where phase measurement is least reliable. The hybrid approach is why modern mirrorless cameras are simultaneously faster and more accurate than either DSLRs or early mirrorless bodies.
Examples in practice
In dim light the camera drives quickly to approximate focus by phase, then makes one small contrast-based correction before locking.