Virtual Private Networks (VPNs) are a type of network technology that allows communication between 2 computers or groups of computers via a public channel, usually the internet. Virtual private networks are a highly customizable, adaptable technology, making them a useful tool for most any business, and VPN information is abundantly available on the internet. To select the right kind of virtual private networks requires an examination of the components of the network technology and the options available.

What is a network? According to Webster's Dictionary, it is "a system of computers interconnected by telephone wires or other means in order to share information." Before the internet, computers in different offices, cities or even countries could talk to each other like people could -through telephone wires.

As the needs for businesses to do that grew, telephone lines became replaced by higher volume wires, like T3 circuits, but the concept was the same. For computer A to talk to computer B, there had to be a physical wire connection. For security reasons, you would want to make sure that only your 2 computers used that line, so you would contract with a vendor to lease that circuit.

With the advent of the internet, connections no longer needed to be physical. As long as each computer on the network has access to the internet, information can be shared using local ISP circuits, across the internet, and to the recipient in much the same way that it was when the computers were physically connected. This is why virtual private networks are "virtual" networks; the entire connection is not hard-wired.

So how do VPNs work in regards to security? In an old WAN arrangement, the security of data transmission could rely entirely on the provider's guarantees. Today, however, VPNs keeps information private by means of encryption on both the sending and receiving end. There are a variety of encryption protocols, depending on what a company's needs are, who they need to communicate with (and therefore be compatible with), etc. The data is not only encrypted, but it is encapsulated, meaning it is sent in its own private "tunnel" or connection across the internet. No one can see the data, and even if they could, they can't decipher or change it. In this way, information can be sent across the internet without being susceptible to interception or corruption by those who are outside of the VPN.

In order to create a virtual private network, you would need to decide who needs to share VPN information and data, in what directions, and how often. Next you would need to prepare a listing of the hardware and software systems you are currently using at each location. You might very well need to make changes so that the computers can talk to each other easily. You'll also want to consider just how important it is that your data remains secure, as this will have an impact on what type of protocol you select, and in turn, the vendor you select. Additional VPN information can be found on the websites of major vendors, or on websites such as that for the VPN Consortium, vpnc.org.