My understanding is that 4D is a kind of energy storage. D stands for dimension. As far as I know, people don’t live in 4D. I wrote an article on it you can find on my home page. Dimensions are hard for me to grasp, just like circular time. I recently wrote about dimensions also recently, but it boggles my brain. That’s one of just a few topics there seems to be a lot of different information on that doesn’t match up very well, and the AAs explained why there’s so much differentiation in accounts. If you have more questions after reading the articles, let me know and I’ll try to help.