Navigation with route calculation and directions from the software to the user of the route to take, based on a vector-based map, normally for motorised vehicles with some motorised forms added on as an afterthought.
Navigation tracking, often with a map "picture" in the background, but showing where you have been, and allowing "routes" to be preprogrammed, giving a line you can follow on the screen. This type can also be used for geocaching.
Terminology
Track
A track is a trace of somewhere that you have actually been. The GPS unit periodically sends details of the location which are recorded by the software, either by taking a reading based on a set time interval, based on a set distance, based on a change in direction by more than a certain angle, or a combination of these. Each point is stored together with its date and time. The resulting track can be displayed as a series of the recorded points or a line connecting them. Retracing your steps is a simple matter of following the track back to the source.
Route
A route is a preset series of points that make up a set route to follow for your destination. Most software allows the route and the track to be displayed at the same time.
Waypoint
Waypoints are used to mark particular locations, typically used as markers along the "way" to somewhere. They are either key entered by users or downloaded from other sources, depending upon the sophistication of the device. Although not linked to tracks or routes, they can be used to simplify the construction of routes, by being able to be re-used. Frequently, waypoints serve a "safety" purpose, enabling a route to be taken around obstacles such as shallow water or streams/cliffs/other hazards which may prevent a safe passage directly from point "A" to point "B".
Navigation software for use on the water has many features in common with land-based GPS navigation software. It can use electronic navigation chart or raster charts, usually provides user ability to plan routes and set waypoints, and may have live GPS tracking capabilities. In addition, marine navigation software often has option to control external autopilot for automated boat navigation. It may incorporate GRIB weather overlay on the chart, Tide predictions and other related information services of additional use to mariners. ;Free open source marine navigation software:
