What does the lock icon mean?

[dmoney]

I'm working with a database that is shared by a number of users.
Occasionally when I go into the internet explorer to pull up the database, a
duplicate file is listed with a tiny lock in the title. Can anyone tell me
what this means?

 

[Douglas J. Steele]

If you look at the details of the file, it should be the same as the
database, but with an extension of ldb, rather than mdb. It's the locking
file, used to ensure multiple users don't try to update the same record
simulataneously.