Users can receive live and on-demand content from the Internet without exposing their company's network to security risks. Many companies and organizations have connected their local area networks, wide area networks, and the Internet together in what is commonly referred to as a global area network. While extremely beneficial in terms of communication and access to information, this interconnectivity can expose a company's network and mission critical information to unauthorized entry and access. A firewall is used to prevent unauthorized accesses. Firewalls are security devices used to protect companies from unauthorized access to their servers.
Many companies use firewalls to control access to their networks and proprietary information.
The firewall's role is to ensure that all communication between an organization's network and the Internet conform to the organization's security policies. With proxy services, the firewall first determines if a requested connection between a computer on the internal network and one on the outside is permitted. If the connection is authorized, the firewall, acting as an intermediary, sets up the necessary communication links between the two computers. As an intermediary, the firewall can monitor the communication between the two networks and suppress any unauthorized activity. For instance, your web browser establishes a TCP connection to a web server.