A Virtual Private Network is a type of computer network that allows users to connect remotely, allowing them the same privileges as if they were sitting a computer physically attached to the network. This can be done for a number of reasons such as enabling students to access course material on a private server, helping colleagues separate by great distances work together and often times VPNs are used to provide a single point for firewalling, filtering and logging.

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There are essentially two types of VPNs; remote-access and site-to-site. Remote access is common among major companies that setup network access servers for their employees to access information or share documents. In this case companies often take use of an enterprise service provider who sets up all the connections and then provides employees with a toll-free number that they can dial into.

Site-to-site VPN can be split up into two types in itself. Site-to-site VPN can either be Intranet based or Extranet based. Intranet based VPNs are utilized when a company has multiple remote locations and wish to use only one network. The company can then create an intranet VPN and connect the LAN from the remote location to the LAN of the central location. Extranet based VPN is utilized when two companies wish to share information that may be used for mutual clients or perhaps to share information involving collaborative projects.