In a multiuser system, when one person is modifying a record, you can set the record locking properties to lock other users out of the record or to verify changes made when two users edit the same record at the same time.
A feature that excludes other users from accessing (or sometimes just writing to ) a record in a file while the first user is accessing that record. ... more
Record locking is the technique of preventing simultaneous access to data in a database, to prevent inconsistent results.