What is Host?
A deprecated Twitch feature that allowed a channel to broadcast another streamer's content while offline. Replaced by the raid feature in 2022.
Hosting was removed from Twitch in October 2022. It previously allowed streamers to display another channel's stream on their own channel page while offline. Unlike raids, hosting didn't redirect viewers — it just embedded the other stream.
Raids have fully replaced hosting as Twitch's streamer-to-streamer sharing feature. If someone asks you to "host" them, they almost certainly mean raid.