A proxy is a computer that acts as an intermediary between your computer and the Internet.
A forward proxy is typically used in an enterprise setting. Enterprise settings often have strict security policies that require all outgoing traffic to go through a proxy server. The forward proxy ensures that all traffic is monitored and controlled by the IT department.
A reverse proxy can act as a firewall between the Internet and a private network, blocking all incoming traffic that the administrator does not expressly permit. In addition, a reverse proxy protects the network from denial-of-service attacks, port scans, and other hacking attempts by blocking direct access to a private network.