Question

what is the difference between 'under' and ' below '

Answer 1

UNDER: Under is used much more widely. When you’re not sure which word to use, use under. It is more likely to be correct. eg. We sat under a tree and rested. 
BELOW: All the common uses of below are related to the idea of “lower or less than. eg. There are many more fish below the surface of the water.

Answer 2

Below | under
1.Below has the same | 1. under is often used
meanings as under, but | to say that something
it's a formal, literary | is covered by another
word.  | thing