In this chapter, we talked about projections. We covered what they are and the various different types of projections. Longitude, latitude, and other geographic concepts were also discussed. While we just scratched the surface of these pretty complex topics, you should have enough fundamental information to understand how to use projections.
We also talked about the Projection class, along with how to transform coordinates and use the Proj4js library. You'll often work with data in coordinate systems other than
EPSG:4326, and knowing how to work with and transform data in other projections is important.
In the next chapter, we'll take a look at Google Maps and other third party APIs, and put some of our recently gained knowledge of projections ...