Final answer:
The DMZ (Demilitarized Zone) is part of a network that contains servers accessible by internal and external users, adding a layer of security between a private network and untrusted networks.
Step-by-step explanation:
The part of the network that is used for servers which are both accessible to internal users, such as employees, and external users, such as clients or customers, is known as the DMZ (Demilitarized Zone). A DMZ is a subnetwork that acts as a buffer zone between a private network and untrusted networks, such as the internet. The purpose of a DMZ is to add an additional layer of security to an organization's local area network (LAN); servers placed in the DMZ are isolated from the LAN but can still communicate with external users.
A firewall is often used to protect the DMZ from unauthorized access, while a router can be used to direct traffic between networks. A hub, on the other hand, is a simple networking device that connects multiple computers within a network, but it does not manage traffic or provide security functions in the way a DMZ, firewall, or router does.