“Broadband” refers to a network that connects users to digital information or other users. We use one every day we read out mail, order something over the Internet, watch Netflix, or visit our children on Facebook. It is a high capacity network, the meaning of “broad.” However, broadband covers a wide variety of networks with an even wider variety of capacities, creating enormous opportunities for confusion. It is rather like the phrase transportation network that can cover everything from city streets to the systems we use for air travel. We are principally interested here in networks fashioned from fiber optic lines, but we will also treat networks designed with legacy telephone and cable television lines and the two principal networks that are nominally “wireless,” our home WiFi network and the various levels of mobile telephone networks, all broadband networks.