In previous versions of 4D all triggers executed in the same process, so they would execute one at a time.

Starting with 4D v11 SQL triggers are no longer serial, they now run in parrallel.

To be more specific, this means that triggers on different tables can execute at the same time. In addition to this, a specific table's trigger can execute in parrallel. This can happen for a specific table, for example, if multiple clients are saving records in a table at the same time.

Note - The terms serial and parrallel are used to describe runtime behavior only.