Provers
Delegated provers: where a wallet that cannot prove itself sends its bundle, and where those machines are
Prover hosts
A pool answers at one address and hands each job to a member host with a free slot, so a host is placed here by the explorer's own list, not discovered on the network. Locations come from each host's public IP; the addresses themselves are not shown.
A delegated prover makes a wallet's bundle proof from a job sealed to its key. It is sent the wallet's viewing key, never its spend key: whoever runs it can read that wallet's history, and nothing more. Anyone can run their own (rand-prover) and pair a wallet with it instead.