Amazon Channels is a subscription service that lets prime members signup for premium services like HBO, Showtime, CuriosityStream, and many others through Amazon Prime. That allow you to manage payments for these services through one app.
The catch in the past was you could only access the content through the Amazon Video app. Now you can use use your Amazon account details to log into HBO NOW if you pay for the HBO Amazon Channel. This gives you the same access to the HBO apps something you could not do in the past. Now with the HBO Amazon Channel you can access to all of their HBO content inside the Amazon Video app and the HBO NOW app.
So what is HBO NOW?
HBO NOW is a streaming service that you pay a monthly subscription for. You don’t need a cable or satellite TV subscription to use HBO NOW.
HBO NOW and HBO GO are available on roughly the same devices and have exactly same content; unlimited access to all of HBO – every episode, every season – plus hit movies, sports, documentaries, and comedy specials.