What is the use of postal codes in Dynamics CRM Field Service?

Postal codes relate to territories. However, they aren’t required for the territories feature to work.

Create postal code records to automatically assign accounts to a service territory. Enter the address on the account form and the system automatically populates the service territory if the postal code matches. You can’t assign a postal code to multiple territories.

Postal Codes In Dynamics CRM Field Service - Aha Apps