It works by listing out streams that people publish. So it’s like an index of peoples streams.
You can either manually stream from your own equipment or use one provided by zap.stream. The latter costs about 10 sats per minute.
Here’s a guide on using it nostr:note13rzyhscm4hf6uua5tnaplfrj344h9l59a5cvh5fe8czm3e78a9vqkpc7ln