This document discusses firewalls and proxy servers, their relationship, types, hardware and software requirements. It defines a firewall as a device or program that filters network traffic to protect systems. A proxy server acts as an intermediary for requests between a user's device and websites. Hardware firewalls are physical devices that can protect entire networks, while software firewalls run on individual systems. Packet filtering and proxy server firewalls are described in terms of their operation and requirements. The document concludes that firewalls and proxy servers both enhance network security but that a proxy server can be integrated into a firewall system.