A virtual private network or VPN is a network that is used to connect nodes. It is constructed using public wires. Many systems enable users to create a network using the Internet. The Internet is used as a means of transporting data. Security mechanism such as encryptations and others are used to make sure that only an authorized person can access the data stored.

Many businesses deal with a global market rather than with just local clients. Most companies today have their business interests spread out across the country or around the world. These companies need a means to conduct fast, secure and reliable communication. VPN provides a convenient way to do so. It is a private network that uses a public network such as the internet to connect remote sites or users together. The VPN technology doesn't use a leased line. Instead, it uses virtual connections routed through the Internet from the private network of the company to the remote site or employee. The advantage of VPN is that it provides an organization with the same capabilities as a leased line, but at a much lower cost.

VPN uses a shared public infrastructure. It maintains privacy through security procedures and tunneling protocols like the Layer Two Tunneling Protocol (L2TP). This protocol sends the data through a ""virtual tunnel"", It encrypts the data before sending it and decrypts it on receiving it at the other end. Security can be further be tightened by encrypting the originating and receiving network addresses.

A secure VPN uses cryptographic tunneling protocols. This provides the necessary confidentiality, prevents unauthorized access and protects private data. Proper selection, implementation and usage of a VPN system can ensure secure communication over an unsecured network. There are many insecure VPN products on the market. Users should thoroughly investigate the products and how secure they are before purchasing any VPN technology.