Rearview and sideview mirrors have been standard auto features since time immemorial, but they don't tell you the whole story about what's going on around you. Mirrors are inevitably subject to blind spots, limited fields of view, and other problems that let dangers slip by undetected.
That's where rear view cameras come in, plus mirror monitors and other equipment that gives you a more robust view of what's going on around your vehicle. This makes driving a whole lot safer, preventing fender benders and removing the hassle from things like backing out of a tight spot.