As robots can have large memory banks, they keep on mapping their location with the help of SLAM technology. So, recording its journeys, it charts maps. This is very helpful when the robot has to chart a similar course in the future.
Further, with GPS, the certainty with regards to the robot’s position is not a guarantee. But SLAM helps determine position. It uses the multi-leveled alignment of sensor data to do so, in the same manner, it creates a map.