Final answer:
Network Address Translation (NAT) is a router technique that allows multiple devices on a local network to use a single public IP address, conserving IP addresses and adding security.
Step-by-step explanation:
The technique used by a router, where NAT translates the home's network's private IP addresses to the single public IP address assigned by the ISP, is known as Network Address Translation (NAT). This method allows multiple devices on a local network to communicate with external networks, such as the internet, using a single public IP address. NAT helps to conserve the limited number of IP addresses available and provides a type of firewall by hiding internal IP addresses from the external network.