A virtual private network (VPN) is a secure network that uses primarily public telecommunication infrastructures, such as the Internet, to provide remote offices or travelling users an access to a central organisational network. VPNs typically require remote users of the network to be authenticated, and often secure data with firewall and encryption technologies to prevent disclosure of private information to unauthorised parties. There are two types of VPNs; remote access VPNs and site to site VPNs. Remote access VPNs are for individual users who are not in a fixed location - remote or roaming users like salespeople. Site to site VPNs are for multiple users in a fixed location - like regional offices. VPNs may serve any network functionality that is found on any network, such as sharing of data and access to network resources, printers, databases, websites, etc. A VPN user typically experiences the central network in a manner that is identical to being connected directly to the central network. VPN technology via the public Internet has replaced the need to requisition and maintain expensive dedicated leased-line telecommunication circuits once typical in wide-area network installations. Virtual private network technology reduces costs because it does not need physical leased lines to connect remote users to an Intranet.[1]