Add a Roku to a TV and your Roku equipped TV gets what you can get with Roku. I had one and gave it away. I wasn't too thrilled about it. Maybe it got better but if you like the name stuff like Netflix, that worked as good as most bluray and Smart TVs with Netflix. But some are thinking about Netflix on their PC and it's slightly different on the Roku.
You don't get the channels you did but I'm sure you understand that.
I have Comcast. Four tvs are hooked to cable, only my main tv has a cable box.
If I purchase Roku what happens with my regular tvs,
Do I remove Comcast, but I still need there cable, phone and Internet. Or drop down to their minimum.