The question of how exactly to explain or define a VPN is often debated among today’s network consumers and communications providers. If we look at the literal definition of the words virtual private network, it can help to understand what a VPN is and is not.

Using Webster’s dictionary definitions of component words, a VPN should have the following attributes:

Virtual – defined as “being such in practice or in effect, although not in reality or name”. Therefore, the first part of the answer to our question “what is a VPN” is that it is something that acts like a wired network, but is not really.

Private: defined as “of, belonging to or relating to a particular person or group; not common or general”. Therefore, a VPN should be one in which the consumer has exclusive use of the network links. (Note that this is different from a secure network, which can be a public or private network.)

Network: defined as “a system of computers interconnected by telephone cables or other means to share information.” This is the goal of a VPN or any other type of network.

The VPN explained in this way is a network technology that gives the owner the ability to share information with others on the network through a private and exclusive link that is created by a method that is not wired or leased lines; generally over the Internet. Before the Internet, computers in different offices, cities, or even countries could only talk to each other as people could: through telephone wires. As the needs for this type of communication grew, telephone lines were replaced by cables of greater volume, such as T3 circuits, but the concept was the same.

In order for computer A to communicate with computer B, there must be a physical wired connection. For security reasons, you’ll want to make sure only your 2 computers use that line, so you would hire a vendor to “lease” that circuit. However, this type of network was expensive and difficult to expand, not to mention difficult for the customer to control.

With the advent of the Internet, connections no longer had to be physical. As long as each computer has access to the Internet, information can be shared using local ISP circuits, over the Internet, and with the recipient in the same way as when the computers were physically connected. This is why the way the VPN works is considered a “virtual” network; the whole connection is not wired.

The VPN aspects explained in this article have so far not discussed an ever-present concern in today’s world: security. In an older WAN configuration, the security of the data transmission could be completely dependent on the vendor’s warranties. Today, however, a VPN keeps information private using encryption at both the sending and receiving end. There are a variety of encryption protocols, depending on what the needs of a company are, who they need to communicate with (and therefore be compatible), etc. The data is not only encrypted, it is also encapsulated, which means that it is sent in its own private “tunnel” or connection over the Internet. No one can see the data, and even if they could, they can’t decrypt or change it. In this way, information can be sent over the Internet without being susceptible to being intercepted or corrupted by those outside the VPN.

To create a virtual private network, you will need to decide who needs to share information, in what directions, and how often. Next, you will need to prepare a list of the hardware and software systems that you are currently using at each location. You may very well need to make changes so that the computers can easily communicate with each other. You will also want to consider how important it is that your data remains secure, as this will have an impact on the type of protocol you select. Preparing this information will educate you for the discussions you will need to have with potential vendors.