Are 4G and 5G radio bands overlapped or completely separated?

Mobility
1

Hi all. I need a simple explanation as a layman for this question.

Are 4G and 5G radio bands overlapped or completely separated?
Is there any easy reference for this query?

2

Sorry what do you exactly mean by overlapped?

3

Like: Can anyone of them be used in same RF band if the other one is not working?

4

You mean multistandard.

5

All LTE bands can be refarmed to 5G.
If it was for example b20in LTE now it will be n20.
This is valid from 1 to 78.