Usually you get 1 set top box included in your plan and a limit on how many devices can stream via the cable app at once (cable is all streaming now in most places, and even many small cable companies have Android and iOS apps to stream for their subscribers). You cannot usually watch cable directly with even a very new TV and coax alone, because its just video streaming over Cable Internet now. Then you pay a rental fee per box for any extra TVs, or if you need to stream to more than the included limit of 3-5 you have to upgrade your plan/package.
Usually you get 1 set top box included in your plan and a limit on how many devices can stream via the cable app at once (cable is all streaming now in most places, and even many small cable companies have Android and iOS apps to stream for their subscribers). You cannot usually watch cable directly with even a very new TV and coax alone, because its just video streaming over Cable Internet now. Then you pay a rental fee per box for any extra TVs, or if you need to stream to more than the included limit of 3-5 you have to upgrade your plan/package.