Geolocation services on mobile devices function through a combination of technologies including GPS, cell tower triangulation, and Wi-Fi positioning. GPS determines the device's location using signals from satellites, while cell tower triangulation estimates position based on the strength of signals from nearby cell towers. Wi-Fi positioning improves accuracy in urban areas by utilizing known Wi-Fi networks. These services enable various applications such as mapping, location tracking, and targeted advertising, enhancing user experience by offering personalized content based on location.