APIPA (Automatic Private IP Addressing) is a feature of Windows that allows devices to automatically assign themselves an IP address if they cannot obtain an IP address from a DHCP server. However, APIPA addresses are not routable, which means that devices with APIPA addresses cannot communicate with devices outside of their local network.
DNS (Domain Name System) is a service that translates domain names into IP addresses. This is necessary for devices to access websites and other resources on the internet.
SMB (Server Message Block) is a protocol that allows devices to share files and printers.
In this case, the technician needs to configure the router to use DHCP so that devices can obtain IP addresses from the router. Once devices have IP addresses, they will be able to access the internet through the router's DNS server.