So if that’s the case, you will need an aerial to access TV channels in your area or at least an indoor Antenna, as simple that. Another thing is that you might find your smart TV connecting well to the Internet and something like Youtube is working fine, but you might face an issue with something like iPlayer and ITV HUB but “this is not always the case but it happens”, the answer is smart televisions use the TV aerial to identify the geographic location. and this will simply help you get the most out of your smart TV running all services properly.
If you are as many as the young generation, you may not probably care much about the local TV. You can just have your smart TV connected to the internet and choose whatever you want to watch from things like Netflix, Amazon, BBC Player, Prime Video, Youtube, or any other built-in app on your smart TV as you will be streaming your content directly from the Internet.