The building is wired by installing numerous network connections (many more than might be needed at present). This not only provides flexibility for the future but also saves money for the largest cost of such a design is the physical installation of the cables themselves.
All of these network connections are therefore individually wired back to a central location into what is often termed a “wiring cabinet” or “wiring closet”. Each network connection is presented on a “patch panel” or “wiring frame”. Contained within this unit will be electrical power and the network components such as switches.
Hence, to enable any given network connection it is a simple case of connecting a wire (a ‘patch lead’) between the network connection point on the wiring frame and one of the ports on the switch. If the hub has sufficient ports then you can, of course, make all network connections live or, you can choose to switch in only those that are required.