GL_TRIANGLE FAN Explanation

Question

I am trying to \"fill\" a surface of a sphere that I drew using this algorithm here: http://paulbourke.net/miscellaneous/sphere_cylinder/, the first method. I know that

Answer 1

How does GL_TRIANGLE_FAN works exactly?

The first vertex of a triangle fan acts like a hub. The vertices following connect with the previous non-starting vertex and the hub.