What does EGL do in the Wayland stack

Recently I drew some diagrams of how an EGL library relates to the Wayland stack. Here I am presenting the Mesa EGL version of them with the details explained.

Mesa EGL with Wayland, and simplified X as comparison.

Wayland misconceptions: Window

There are many misconceptions about Wayland, and I want to try to correct one. Let's start with the statement:

There is no object in the Wayland protocol that corresponds to Window in X.

Surprised? We need to take a step back to explain what that really means, and I will do it with the help of an example of a complex application: Firefox.