Although they are both owned by the same company, they have entirely different targets. Twitch is available for any user to join and create their own content, which means that anyone can create a channel and stream what they like. So I popular Twitch channels are focused on a player playing games or streamers talking with their followers. For the other part, the content streamed on Amazon Prime Video, is produced by the company, and is more like the content you can find on cable TV. With studio productions and bigger budgets, the streams of Amazon Prime are bigger, and usually if a higher quality.