All devices connecting to a wireless router must possess a working network adapter. As illustrated in the diagram, connecting to the router a broadband modem (that has one or more built-in adapters) enables sharing of a high-speed Internet connection.
Wireless routers technically allow dozens of computers to connect over WiFi links. Nearly any residential wireless router will have no trouble supporting the number of wireless devices found in typical homes. However, if all WiFi computers attempt to use the network at the same time, slowdowns in performance should be expected.
Many (but not all) wireless network routers also allow up to four wired devices to be connected via Ethernet cable. When first installing this kind of home network, one computer should be cabled to the wireless router temporarily to allow initial configuration of the wireless features. Employing Ethernet connections after that is optional. Using permanent Ethernet connections make sense when the computer, printer or other device lacks WiFi capability or cannot receive an adequate wireless radio signal from the router.
Optional Components - Networking the router for Internet access, printers, game consoles and other entertainment devices is not required for the rest of the home network to function. Simply omit any of these components shown that do not exist in your layout.
Limitations - The WiFi portion of the network will function only to the limit of the wireless router's range. The range of WiFi equipment varies depending on many factors including layout of the home and any radio interference that may be present.
If the wireless router does not support enough Ethernet connections for you needs, add a secondary device like a network switch to expand the wired portion of the layout.