As workforces get more and more decentralized and telecommuting becomes more widespread, businesses of all sizes have come to depend on virtual private networks, or VPNs. A VPN is a secure, private network that runs on a public network (usually the Internet). VPNs can allow remote workers secure access to your network, just as if they were at their desks in your office. If you or your employees are routinely away from your office and need access to your company's network, a VPN is an inexpensive way to increase productivity — without sacrificing security.

The name "virtual private network" gives you a clue about how VPNs actually work. VPN software programs "carve out" a section of the Web, and allow only authorized users to access it. This virtual network runs on top of an existing network and is private. Hence the name.

Users who provide the correct login information are granted access to the VPN gateway at the office. Once they're connected though the gateway, they can access the network just as if they were at their desks — reading and sending e-mail, opening and storing files, or working on specific local applications.