Because at this stage we have a VERY limited set of tools to measure, see or describe these biofields, we naturally tend to simplify them.
Imagine now that every cell or process in your body has a biofield.
Imagine that each one of your thoughts or emotions changes the vibration in your biofield.
You can look at your overall aura and describe the overall vibration or you can dive into microcosmic dimensions and describe the vibration of a cell or part of it.
The complexity of your biofield is immense!
It is at least as complex or even more than you phyiscal anatomy.