You may need to read the previous articles about cubemaps and framebuffers in order to understand this one.

Shadow maps

The most common way to draw shadows is with shadow maps. Using a shadow map is similar to projecting a texture, but the texture contains depth data from the point of view of a light (located at the tip of the frustum).

This article is a work-in-progress. In the meantime, consider reading these other articles about the same topic:

The next article is about fog.