The world has changed a lot in the last couple of decades. Instead of simply dealing with local or regional concerns, many businesses now have to think about global markets and logistics.
Many companies have facilities spread out across the country or even around the world.
A WAN had obvious advantages over a public network like the Internet when it came to reliability, performance and security. But maintaining a WAN, particularly when using leased lines, can become quite expensive and often rises in cost as the distance between the offices increases. As the popularity of the Internet grew, businesses turned to it as a means of extending their own networks. First came intranets , which are password-protected sites designed for use only by company employees. Inc. A typical VPN might have a main LAN at the corporate headquarters of a company, other LANs at remote offices or facilities and individual users connecting from out in the field.