Exchange EDB file is the main repository of Exchange Server database , this EDB file includes the entire data components like email messages, folders, attachments.
In data recovery aspect, losing it can mean a loss of valuable stuff.
The windows edb file is a database file contains the indexing service.
In data recovery aspect, I can not think of a reason - if someone lost it - to pay a dime for it.
B.T.W. their signature is the same: 0xEF 0xCD 0xAB 0x89 at offset 0x04