What is ng-eNodeB?

What is ng-eNodeB?
I.e. upgraded 4G base station used in option 5?
Is it 4G eNodeB or 4G eNodeB upgraded to 5G in term of hardware?
Term not clear, please elaborate 5G experts…

ng-eNB which can connect to 5GC through NG interface.

You can take a look at this article:

eNB that is connected to Xn and NG is called “ng-eNB”.
An ng-eNB, providing E-UTRA user plane and control plane protocol terminations towards the UE.
ng-eNB (also referred to as eLTE eNB) is the evolution of eNB that supports connectivity to LTE Core Network (EPC) and 5GC.