There are four basic elements of nature: fire, air, earth, and water. Within each of the four elements are nature spirits that are the spiritual essence of that element. They are made up of etheric substance that is unique and specific to their particular element. They are living entities often times resembling humans in shape but inhabiting a world of their own.
The beings in the Elemental Kingdom work primarily on the mental plane and are known as "builders of form." Their specialty is translating thought-forms into physical forms by transforming mental patterns into etheric and then physical patterns. Each of them is a specialist in creating some specific form whether it be an electron or interstellar space.
Elementals range in size from smaller than an electron to vaster than galactic space. Like the angels, elemental beings begin their evolution small in size and increase their size as they evolve. The elementals serving on planet Earth materialize whatever they pick up from the thoughts and feelings of mankind. This relationship was intended to facilitate the re manifestation of "heaven on Earth."
They take their orders from the devas.
They do not remain individualized as humans are. These beings are animated by the thought power of the lower angels and so are thought forms of sorts.
They may be etheric thoughts forms, yet they have etheric flesh, blood, and bones. They live, propagate off spring, eat, talk, act, and sleep. They cannot be destroyed by frosser material elements such as fire, air, earth, and water because they are etheric in nature. they are not immortal. When their work is finished they are absorbed back into the ocean of spirit. They do live a very long time--300 to 1,000 years.
They have the power to change their size and appearance almost at will. They cannot, however, change elements.