Geolocation is the practice of establishing exactly where a photo or a piece of video footage was captured. An image can be geolocated by studying its content, by comparing it to others, or by looking at clues outside of the image, such as who shared it, or where it was found. Geolocation typically ends with the location of the image on a GIS platform based on a satellite image.
Bellingcat’s Eliot Higgins published a beginners’ guide to video geolocation here.