Read this page to get a full overview: https://www.hornetstorage.com/protocol

“Hornet storage operates beneath Nostr, storing relay data as Merkle DAGs/Trees in its key-value database. The relay manager lets operators view data usage by service and select which services to host.

Data is tagged with a credential indicating its service type, such as "nostr note" for posts, "nostrtube" for a nostr YouTube video, "stemstr" for a stemstr music note, "git" for a git repository folder, et al.” 🐝