How maps work
This is an intro to digital maps. It’s for everyone and doesn’t require any previous knowledge. This page should provide enough information to help you understand the basics needed for building, customizing, and implementing maps.
How a map gets displayed
In contrast to paper maps, a digital map is usually interactive, allowing you to zoom and pan (move around). However, a single map of the entire world would be too big and too slow to display. So how does it work?
In short, the world is divided into small squares called map tiles, and your browser only loads tiles needed for the current view and zoom level. It’s fast and you get an illusion of exploring a single large map.
Learn more:
- Tiles à la Google Maps: How exactly zoomable maps work and what is map projection
- Map coordinate systems: What they are and how they relate to map projection
What a map consists of
A map is essentially a combination of two things: map data (what is displayed on the map) and map style (how it is displayed). The relation of these two components is crucial for understanding how to customize a map or add something to it.
Map data
Map data is the information and material to build a map with. It comes in datasets of various types, and determines what you can see on the map. If a dataset contains information about countries (their names and location of borders), then the map can show countries. If a dataset contains information about the floors of water bodies, then the oceans on the map can have a shaded profile indicating depth rather than just flat blue color.
The most important type of dataset is a tileset. Each tileset holds a set of map tiles of the same type for a certain area. The tiles can be in either vector (geometries) or raster format (standard images). At MapTiler, we keep a range of professionally maintained and regularly updated global tilesets which are the data backbone of our maps. You can purchase them for your on-prem maps, too. Also, you can create new tilesets from your own data and then combine them with our tilesets to create exactly the map you need.
The other basic dataset type is vector features. It’s a single file, not tiled, and contains individual map features in geometric shapes such as points and lines. Thanks to its simplicity, this format is ideal if you want to define your own custom features to show on the map.
Learn more:
Map style
Map style is the cartographic design applied to the map data. If you’re showing countries, how thick should the borders be and in what color? If you include country names, what font to use for the labels, and in which language to display them? What shade of blue and which level of transparency for the water areas?
In practice, the map design is organized into layers. Each layer describes 1. what source to get the data from, 2. how to display it. For example, a map layer can pull cycling paths from the MapTiler Outdoor tileset, and define that the paths will be styled in certain colors based on their difficulty. Definitions of all the layers then get consolidated into a single map style document (JSON) which represents your map.
Note that the terms map and map style are often used interchangeably. For example, the Streets map is in fact a streets.json file (map style document) which describes how the map should look, so we can refer to it as “the Streets map” or “the Streets map style”, depending on situation.
Learn more:
Visual effects
Once you have a map with the desired design, you may want to add some special effects, for example an elaborate visualization of your data or fly-through animation. This requires adding code for the desired effect or functionality, which is usually the job of a developer. We cover everything related to that job in the developer’s section of this documentation.
What’s next?
Now that you know the basic concepts and terminology of map building, you can go ahead and customize your selected map by adjusting its design or by adding your own data to it. Or both, of course. Happy mapping!