This chapter mainly deals with the characterising the Valar and how they built their dwellings and shaped Valinor. It also touches upon some tasks of the Valar. Some key elments in the chapter regards brining light to the world by he use of two Lamps and later the Trees of Light.
This passage is basically the first part of the creation myth that Tolkien designed for the world he wrote about. It tells about how Ilúvatar sang the Ainur into being and how the world and elements became real. The story mainly deals with Ilúvatar's vision and design of the world - through music.