Essentially the difference between invocation and possession is control and intensity. In invocation you are still fully in control, but in possession you are allowing the presence of the entity to intensify within you and overwhelming you.
Through techniques such as trance work, sound, the use of mind altering substances and so forth you can enter into that extremely sensitive state wherein through disassociating the self from the self, you relinquish control over to the spirit. Not by just saying “spirit I give you control” cause that’s just a statement but it takes time and patience to be able to relinquish control over words, actions, thoughts etc.
At this point your words will no longer be yours, your ideas, thoughts or concepts, nor your movements or actions. The intensity of the possession once again depends upon the level of intensity of the method/the ritual or the state not to mention how immersed you are in the moment.
