Global Positioning System (GPS) is a satellite based navigation system. GPS is used in guiding & mapping applications and also used in location services. In present days, GPS is not only provide the position but GPS is also used in various applications in computer science like wireless video processing & monitoring using mobile, localization of automobile, in fisheries & marine studies, in IEEE 802.11 networks, in auto regressive ionospheric prediction model etc. GPS & all above applications are discussed in this paper.