Acts like a single network, but spans across multiple physical locations
Wan technologies usually require that you contract a link across the Internet with your ISP. This ISP handle sending your data from one site to other.
A typical WAN setup has a few sections. Each of the networks ends at a demarcation point which is where the ISPs Network takes over. The are between each demarcation point and the ISP’s actual core network is called a local loop. This local loop would be something like a T carrier line or a high speed optical connection to the provider’s local regional office.
WANs work by using a number of different protocols at the data link layer to transport your data from one site to another. In fact, these same protocols are what are sometimes at work at the core of Internet instead of our more familiar ethernet.