Concurrent Transactions

Concurrent transactions are transactions that occur at the same time, such as shared multiple users accessing shared objects.

As an example, if two people are updating the same catalog item, it's not acceptable for one person's changes to be "clobbered" when the second person saves a different set of changes. Both users should be able to work in isolation, working as though he or she is the only user. Each set of changes must be isolated from those of the other users.