The DB is being saved in Dropbox so that it can be accessed from various places. I am planning to give access to the dropbox account to 2 other persons, so that they can open the database file.
But this does not actually "share" the database. Say user 1 opens the database from drop box. Then user 2 opens it. They both now have distinctly separate copies of the database. When they both close the database, you'll find that you have two copies of the same file (one named "conflicted copy...") in your drop box folder and the data will not be identical in the two if both users have modified records in different ways.
To share the database file, move a copy out of drop box and use it as a place to save back up copies of your database. You'll need to open the file with FileMaker Pro on one computer and then other users can use Open Remote to access and open the database up to a limit of 9 other users--including FM GO clients of iOS devices such as an iPhone. (In FileMaker 13, this limit drops to 4 other users.)
The other option is to use IWP--a technology no longer supported by FileMaker in versions newer than 12 as they have replaced it with WebDirect to host database to the intranet or the web. Then users with web browsers--up to the same limit, can access the database. IWP is much more limited than straight FileMaker with FileMaker clients.
thanks for replying