Density refers to the etheric vibrational frequency spectrum, organized into various bands or octaves over which all existence is experienced. "Density" denotes a vibrational frequency, not to be confused with "a location in time and space" which the term "dimension" traditionally implies. All forms of energy have a particular range of vibrational density or frequency - minerals, plants, animals, humans, extraterrestrials, celestial Beings, etc. Density bands describe a range of frequencies...for example, the 4th band of density ranges from 4.0 to 4.99, the 5th from 5.0 to 5.99 and so on. As examples, current human physical bodies function in the 3rd and 4th density bands. Ascended Masters function in 9th, Maitreya functions in 10th, and Universal Source functions in 11th.