PP,
First you buy a ROKU ranging in price from less than $100 and up. Then YOU become a ROKU USER.
The ROKU CHANNEL is an app for your purchased ROKU. No subscription charges for the channel, nothing to purchase the actual app.
You will need an adequate internet connection for streaming.
ROKU has a number of channels which are offered at no cost to you. Some app channels do require that you be hooked into cable in order to view. ROKU, OTA Antenna, and You Tube should be ALL you need to become a “Couch George” and sit watching the tube till your heart’s content.
Thanks - Costco has a premiere m Roku- Ill pick one up