We have O365 licenses and using platforms like OneDrive for Business and SharePoint Online. I know that the OneDrive for Business sitecollections underwater just SharePoint sitecollections. Are the OneDrive for Business sitecollections part of the SharePoint Online overall storage?
No, OneDrive storage does not count towards your used SharePoint quota. However, the OneDrive storage is intended for personal use and should not be used as a storage for corporate data (part of the contract).