Final answer:
The network to be connected to the firewall and separate from the LAN as described is a Demilitarized Zone (DMZ), which aims to provide an additional security layer to protect internal networks from external threats.
Step-by-step explanation:
The type of network described in the question, which is a network connected to the firewall and separate from the LAN, is known as a Demilitarized Zone (DMZ). A DMZ is a physical or logical subnetwork that contains and exposes an organization's external-facing services to an untrusted network, usually the internet.
The purpose of a DMZ is to add an additional layer of security to an organization's local area network (LAN): an external attacker only has access to equipment in the DMZ, rather than any other part of the network.