IIRC the recent Chinese landers used LIDAR and feature matching during the terminal phase. As for spacecraft navigation in general you are using star/sun/earth

IIRC the recent Chinese landers used LIDAR and feature matching during the terminal phase. As for spacecraft navigation in general you are using star/sun/earth trackers (depending of where your spacecraft operates) to detect your orientation. This is important to correctly point solar panels to the sun, radiators, cameras and sensitive instruments away from the sun and directional cameras to Earth. As for detailed absolute position in space, AFAIK this is usually done by ultra sensitive radio signal ranging back on Earth. But other means could be used, eq. taking picture of your target or other bodies you can resolve and then tracking their magnitude/size and position, possibly over time, to calculate where exactly you are in the Solar System so that you are seeing what you are seeing.