One of the leading theories concernng what orbs are is that they are not the spirit at all. The orb is the energy being transferred from the source(powerlines, heat energy, batteries, people etc.) to the spirit so they can manifest.  This may not even be a consious thing the spirit is doing, just a natural way they get their energy,  This would explain why the orbs are round balls, according to the laws of physics energy being transferred would assume its natural shape of a sphere.

Many researchers believe that an orb is a ghost in its true form.  Until now most researchers knew that what they were seeing were ghosts, but they didn't know much about them.  They are just learning now to use infrared or ultraviolet technology to track these entities.  Researcher Michael Lynch has studied an MRI and PET scan of a human and a thermal scan of an orb and found many similarities.

Our brain is essentially what makes us who we are.  It is our identity.  As a human develops, his or her brain size increases.  The same idea may go for ghosts.  Ghosts may get bigger as they age in their plane of existence.  They can become as big as they want when they learn how and have enough energy.  The ghost can manifest to be what it thinks it to be, but this takes a large amount of energy. 

Another paranormal aspect of orbs is the speed and way they move.  While some move slowly in every direction possible, others move quickly.  This has been documented and captured on film, with an anomoly moving at 300 feet per second.

When looking at what is consdidered a paranormal or spirit orb, one can see that it seems to be comprised of and structured into 3 main parts.

The outer layer (like a ring) can appear as a cloud or white mass.  It can also appear to be more transparent .  Some refer to this as the "field effect"  The next layer is very interesting because it tends to have a "stringy" or "angel-hair" look to it.  Some researchers believe that this layer is what gives you the cold feeling.  The idea being that this is the enitity's sensory layer, in which it collects data from its surroundings through energy fields.  Finally, there is the center layer, this appears almost as a nucleus of the orb or the "central matrix".  This could very well be the core of the mind of the entity, where the identity of it lies. 

Now taking that explanation of what an orb is made of, can we perhaps individulaize and identify a ghost?  A group called SEARCHERS believes that it is possible by looking at the orbs central matrix and field affect.

Since we do not know what orbs truly are, just that they seem to be found mainly in areas where there is high spirit activity.