Pin maps, also known as pinpoint maps or location maps, show the exact location of things.
Pin maps are becoming more and more popular, as more data sources, especially those from mobile phones or smart phones, include exact locations. Twitter posts and Flickr photos, for example, are commonly mapped using pinpoint locations.
Another ubiquitous version of a pin map is a searchable online map, such as Google maps, Mapquest maps, or Bing maps that show the exact location of the items being searched for. GPS units also use pin map techniques when they show the unit’s position.
Connection maps are similar to pinpoint maps, except the points have connections between them. These maps are essentially graph or network data drawn with a geo-spatial layout. Often the connections are abstract, such as phone calls or tweet replies, so the connections are represented on the map with an arc or straight line.
Subway maps are another version of connection maps. The connection is most important in these maps, although the precise station location is not. Subway and transit maps are always manually created by designers who simplify the routes down to lines at a few different angles, making the map much more legible for the important information.