The LiDAR sensor is only on the 12 Pro and 12 Pro Max. In addition to aiding with augmented reality applications, the sensor also helps with speeding up autofocusing, especially in the dark. Apple says autofocus is up to 6x faster thanks to LiDAR. The sensor also enables Night mode for portrait mode photos.
All four iPhones have taken a big step in durability with the addition of a "Ceramic Shield" front cover. According to Apple, a new "high-temperature crystallization step" increases the crystals inside the glass and bolsters drop performance by 4x. Scratch resistance, however, is the same as on iPhone 11 and 11 Pro.
MagSafe (originally featured in the original MacBooks in 2006) is meant to help optimize charging by ensuring that the wireless charger is always aligned properly to the back of the phone where the charging coil is. According to Apple, Belkin will also be developing accessories that include a car mount and dock.