Hi I would like to know how the ledger nano works exactly? What is the route of a transaction, how does it reach a given blockchain.

For example if I send a bitcoin transaction with a ledger nano, I don't have the block chain or a full node on my ledger nano or computer and I can see the ledger nano uses different ports to send the signal to a cloudfare ip address. So it doesn't seem to be broadcasting the transaction directly to the blockchain but pass through some kind of protected server...

Does anyone know how it works or how this kind of wallet work in general to broadcast the transaction, I guess ligth wallets kind of work thaty way too.

if they use servers, how many are they? 2-3 or hundreds of them?