A router is a networking device that connects remote locations together. They can be locations from the same company or through the Internet. Many routers now include a built in firewall. This is a hardware security feature that is designed to prevent unauthorized users from accessing your local network and also provides filtering of many forms of computer infections. Most people are familiar with the home routers used to connect to the Internet. Business grade routers are more complex and provide greater degrees of network security and configuration flexibility.