.db

.db is a filename extension that refers to some sort of database file. [ [http://www.fileinfo.net/extension/db Fileinfo.net - db] ] Oracle saves databases as .db, as do a variety of other programs.

Thumbs.db [ [http://www.eToolkit.net/computer/file_extension/db.htm eToolkitnet - db Extension] ] is a file Windows uses to store thumbnail images of folder contents.

References

r.b.