noun - A waypoint is a reference point in physical space used for purposes of navigation.
Waypoints are sets of coordinates that identify a point in physical space. Waypoints have become widespread for navigational use by the layman since the development of advanced navigational systems, such as the Global Positioning System (GPS). Waypoints located on the surface of the Earth are usually defined in two dimensions (e.g., longitude and latitude).
In the modern world, waypoints are becoming increasingly abstract, often having no relationship to any distinctive features of the real world. These waypoints are used to help define invisible routing paths for navigation. For example, artificial airways—“highways in the sky” created specifically for purposes of air navigation—often have no clear connection to features of the real world, and consist only of a series of abstract waypoints in the sky through which pilots navigate; these airways are designed to facilitate air traffic control and routing of traffic between heavily traveled locations, and do not reference natural terrain features. Abstract waypoints of this kind have been made practical by modern navigation technologies, such as land-based radio beacons and GPS.
Abstract waypoints typically have only specified longitude and latitude or UTM coordinates plus the reference datum, and often a name if they are marked on charts, and are located using a radio navigation system such as a VOR or GPS receiver. A waypoint can be a destination, a fix along a planned course used to make a journey, or simply a point of reference useful for navigation.
Waypoints and GPS
GPS systems are increasingly used to create and use waypoints in navigation of all kinds. A typical GPS receiver can locate a waypoint with an accuracy of three meters or better when used with land-based assisting technologies such as the Wide Area Augmentation System (WAAS). Waypoints can also be marked on a computer mapping program and uploaded to the GPS receiver, marked on the receiver's own internal map, or entered manually on the device as a pair of coordinates.
Many GPS receivers, both military and civilian, now offer integrated cartographic databases (also known as base maps), allowing users to locate a point on a map and define it as a waypoint.