What is a reverse firewall and why would you use one?

What will be an ideal response?

Some forward-thinking companies install a reverse firewall, a device that monitors outgoing connections instead of trying to block incoming traffic. Sometimes the biggest threats to an internal network come from its own users. For example, a university might make certain applications available only to researchers and scientists who need them. Clever computer science students might try to break into the server that stores these applications so they can download the applications and use them. A reverse firewall would help by monitoring outgoing connection attempts that originate from internal users and then filtering out unauthorized attempts. Reverse firewalls have other purposes as well. For example, a company that is concerned about how its employees use the Web and other Internet services can set up a reverse firewall to log connections to Web sites. It can then block sites that are accessed repeatedly but are considered unsuitable for employees to visit during work hours.