WiFi can be used to bridge between two networks. For instance, one building with a network and internet access has another building connect to it so it also can access the internet. This can be a factory connecting to the office building, or a milking shed to the main home. Distances of 5Km can easily be bridged with relatively low-cost equipment, although longer distances of 30+ KMs can be achieved.
One example of a WiFi bridge is this; picture a factory in a valley where there is no internet connectivity. Not by wire or wireless. On a hill next to factory is strong Mobile Broadband signal, but this does not reach the valley the factory is in. A mast can be installed with a solar panel and batteries on the hill to create one side of the WiFi bridge.
Then a Mobile Broadband router is installed to connect to the internet. This can also be a fiber, or Starlink connection. Connected to this internet link is one part of the WiFi bridge. This bridge then connects to the second WiFi part connected to the factory in the valley. When the WiFi bridge is connected between the factory in the valley and the internet connection at the top of the hill, the factory has internet access!
Area coverage
WiFi is very useful to cover an area where network access is required. This is very cost effective as there are no on-going costs involved. An area can be covered using multiple Access Points (AP's) to make sure that there are no areas that do not have coverage for connectivity. This can be good in warehouses or factories where cabling is problematic or vehicles and users that are on the move all the time.