Port address translation (PAT) allows multiple devices on a local network to be mapped to a single public IP address with different ports. This technique is commonly used in small business networks to economize on the number of public IP addresses required and to add a layer of security by hiding internal IP structures. NAT was a close option but doesn't specify the usage of a single address for multiple connections, which is the specific requirement in this scenario. Dynamic routing and VLAN tagging are not directly related to the translation of IP addresses or the efficient usage of a single IP for multiple connections.