A raid sends your live audience to another channel when your stream ends: one command, and everyone lands in someone else's room together. It's Twitch's built-in generosity machine, and the main organic way small channels inherit viewers.
As you end a stream, you pick a target channel and start the raid. Your viewers arrive together, announced in the target's chat, often with a shared message or emote ritual.
For the receiving channel it's a sudden room full of real concurrent viewers, plus an endorsement: someone whose taste their audience trusts chose this room.
Raid viewers arrive pre-endorsed, which converts to follows at rates cold discovery never touches. For channels grinding toward the Affiliate average-viewers bar, raid relationships are one of the few levers that move the hard metric, not just the follower count.
The culture is reciprocal: channels that raid get raided. Networking with streamers your size in your category IS the strategy; the button just executes it.
Yes, while they stay: they're real concurrent viewers. The 30-day average still needs regulars; raids are a boost, not a foundation.
Yes, Twitch has settings to limit who can raid you, built as harassment protection.
Hosting (showing another stream on your channel) was retired by Twitch; raiding, which physically moves the audience, is the surviving mechanic.
Every definition lives in the full glossary, and the services behind the vocabulary are on the services page.