First, there was nothing except Emptiness. This large Emptiness was filled with atoms and particles. Then, within this Emptiness, the Power of Elemental Wind was established first. Because of the Power of the Wind, all of the atoms combined together. This was the basis for our kind of Universe.
Usually the friction of two Elements can generate heat. Similarly, the Wind was moving very fast within the Emptiness, which caused tremendous heat. Thereby, Elemental Fire was established.
Whenever there is warmth, it can evaporate. Thereby clouds are created. When there are clouds, water is generated. Then, we have the Water Element. One may wonder, how can Earth be established on the face of Water? Earth is like the cream of milk. If we have milk, there will be cream. Therefore, the Earth is a cream of the Water.
Following the establishment of the Earth, the different mountains were created. The Earth contained Gold, Silver, Copper, Brass & Iron. These are considered to be part of the Precious Elements. Of these Elements, Gold is considered to be the most precious.
Buddha dwelled with great length talking about Buddhist Cosmology in such Tantras as the Kalachacra. On the basis of that weight, this explains how the universe was created starting from the bottom upwards.
Now concerning the contents of the Earth, such as human beings - it is regarded that we descended from the top of the universe.
There are three different Realms. These are the Realms of Desire, Form & Formlessness.
We belong to the Realm of Desire, which has six different categories within it. Some of the categories include: The World of Human Beings, The World of Animals, The World of Greed, The World of Hell, etc.
Within The Realm of Form there are seventeen different categories. One of these categories includes "the Gods of Divine Power." They talk about the different meditational stages of Bummis. This Divine Realm has eight categories starting from one to eight. In regards to physical appearance, they are nine times better than us.
With regard to the Realm of Formlessness there are four different categories. Beings existing there are Formless and so they depend upon the power of meditation because they don't have a body.
The three Realms of Desire, Form & Formlessness are also known as the Realms of Cyclic Existence.