Depending on the use, GPS navigators them can be classified in the following way: common use GPS navigators are portable devices with basic location functions. They weigh little, install easily and are cheap. You can use them on routes on foot and bicycle. The screens are smaller and data are difficult to see. They have no voice instructions. Automotive GPS are the most popular GPS.
Sold with pre installed maps of specific geographical areas. Navigation instructions are given by voice signals. The browser allows you to set different profiles of navigation. Longest route, shortest route. Some browsers incorporate advertisers of radars.
GPS marine are GPS designed for marine use. They have a large hard disk that stored many maps. They are protected against water.