A precisely arranged ring of magnets embedded in every compatible iPhone from the 12 onwards is what makes MagSafe work — and what makes it different. Those magnets serve two functions simultaneously: they centre the device on the charger with enough accuracy that the charging coils on both surfaces align correctly every time, and they hold the connection firm enough to resist incidental movement without requiring any physical connector. The underlying charging technology is Qi — the established wireless inductive standard — but standard Qi allows for positional slop that reduces efficiency and generates heat. MagSafe eliminates that slop. By snapping the device to an exact position, it ensures the transmitter and receiver coils are concentric, which is the condition under which inductive power transfer works at its highest efficiency.