INTRODUCTION It was developed by the United States Department of Defense in 1969 for military applications. The system was made available in the 1980s for civilian use, a decade after its development. It is also called NAVSTAR (Navigation System, Timing and Ranging). Orbiting navigation satellites are used in this system to transmit position and time data to portable devices or receivers. Handheld devices or receivers calculate latitude, longitude, altitude and speed itself based on orbiting navigation satellites. GPS system helps in navigation, routing, control. GPS works around the clock, in any weather condition and anywhere in the world. The first four satellites were launched in 1978 via the Delta rocket. The first satellite was named NAVSTAR 1. The system became fully operational on June 26, 1993 after the launch of the 24th satellite. To locate the position in three dimensions, at least 4 GPS satellite signals are required. The accuracy and precision of the data increases as the number of satellites increases. Before GPS (Global Positioning System) devices came into existence, traveling to unknown places was nothing but going on an adventure, after these devices were commercialized, people's dependence on them grew significantly and the transportation system has made great strides around the world. GPS devices are used in our daily life for various purposes such as road navigation, location finding, tracking, mapping, etc. This report is aimed at anyone who is curious or uses GPS devices to know how these devices came into being, how they work and their reliability. This report is about the Global Positioning System (GPS) used in GPS devices and contains details on what GPS is, its brief history, how... middle of paper... which is still evolving as it is combined with many other technologies to be used in many other applications. The modern world is increasingly dependent on GPS and the future without it is no longer possible. Although there are countries that are still a little behind in the commercial use of GPS in daily life, there will definitely be a time when these countries will also develop and adapt to this modern technology, there are some countries that are reluctant to use GPS but they have their own versions of GPS like Galileo in Europe and GLUNAS in Russia. GPS is a perfect example of the statement “any war machine can be used for peaceful purposes” since GPS was initially developed for warfare purposes. GPS is a revolutionary advantage for transportation system which is spreading to various other fields and will continue to grow for a better tomorrow.