Physical cables form the backbone of virtually every network in existence. While wireless links may be more appropriate for certain situations (for example, establishing communication between ground stations and satellites), wired media typically constitutes the vast majority of links in a network. This wired media can be broadly categorized into two main groups—copper cables and fiber cables.
In the following subsections, we will discuss both of these broad categories of cables, the termination points and connectors that each of them use, and the various standards and transceivers associated with each category.