The AND gateway models the branching type “and”.
In case of branching all originating edges of the gateway are activated.

example:
After a customercall is answered, the responsible worker has to simultaneously find out the customer's wiches and also enter the order into the sytsem.

Waits on a merger until all incoming edges are finished, before activating the outgoing sequence.

example:
Only after findingt out all of the customer's wishes and all orders are entered into the system, the call is ended.