My personal experiences agree with much of this author's descriptions so I decided to quote him on orbs. Later on he mentions the orbs in relation to abductions and modern ufo phenomena as well- though that's not my point of interest.
I read this by Marcus Cordey:
The Fay are spirits who dwell in part of the Astral World which has been termed Faery, or more
commonly, the Fairylands. Because of their connection to the life-force of Earth, however, Fay
often crossover and can found in forests or wilderness, often appearing as orbs of light, or curious looking,
diminutive humanoid beings. The word "Faery" is the actual name of "the Realm of the
Fay" and is not the name of the type of creature itself.
Though the word "fairy" is today used as a generic term for any sort of being that is like a Fay, this word conjures up
an inaccurate mental image of these beings. Thus, the term "Fay" is preferable.
It should now be pointed out that the Fay of European antiquity in no way resembled the flighty,
dragonfly winged "fairies" that are seen in children's books today. The Fay are native astral
beings, and appear to have the ability to manifest in the physical world. The three most common
forms are the "flying orbs", tall Nordic elves, or the traditional diminutive "little people". In olden
days, the Fay were said to be able to greatly benefit farmers, midwives, and witches (if appeased),
performing various tasks such as keeping away pests, ensuring good health, and generally
providing an air of luck and good fortune. However, faery beings were, by and large, something to
be feared. Men and woman who encountered the Fay in the woods often disappeared, never to
return to the mortal world. Other times, the Fay would abduct newborn babies, replacing the infant
with a strange likeness called a "changeling" which would die some time after. The reason for the
abduction of babies (and even adults) is unknown, but from their behavior it would appear to have
something to do with reproduction, either of their own race or a study of ours.
This is just one perspective. Like I said, I'm not sure. It could be orbs are a variety of things; different spirits using a common manifestation? Maybe its the simplest form for a spirit to take? Though, in the only verifiable experiences I know of, the orbs were always surrounding a greater entity like the Shakti godesses on the astral plane, or secondary physical emanations of elemental evocations. Remember elemental spirits can be enormously powerful spirits. They can include archangels, angels, elemental kings, all the way down to the gnomes or other variety of terrestrial spirits. A lot of spirits have an elemental nature that can be contacted, sometimes under a different form. Like the archangels of the quadrants are not exclusively elemental spirits but they do have an aspect that serves in the elemental hierarchy. I found that evoking into a crystal on the triangle of art allows contact with the greatest variety of spirits. Adding(vibrating) Enochian during the conjurations causes a dramatic increase in the visuals and the amount of images for me. If you ever get a chance, I recommend doing some exploring this way. It's always been a very beneficial learning experience for me, as well as confidence building.
I have heard from a few (reliable)sources about orbs appearing - during demonic evocations to the physical, during a group ceremony, and poltergeists. I'm open to anything. I'd like to know what anyone has to offer on the orbs.