The book
Open offers.
Every ask and bid on the desk contract. Nothing here comes from a server: the page reads the contract's storage on BNB Chain.
Every ask and bid on the Solana desk. Offers are signed by their makers and kept by the desk API; every fill settles on chain in one transaction.
Your wallet
Your approvals.
What the desk is allowed to move from your wallet, token by token. The desk can only use an approval inside a fill of an ask you posted, paid in the same transaction. Revoke sets it back to zero. Any ask you still have open on that token then can no longer be filled, so cancel it too.