To create and transmit an onion, the originator selects a set of nodes from a list provided by a "directory node". The chosen nodes are arranged into a path, called a "chain" or "circuit", through which the message will be transmitted. To preserve the anonymity of the sender, no node in the circuit is able to tell whether the node before it is the originator or another intermediary like itself. Likewise, no node in the circuit is able to tell how many other nodes are in the circuit and only the final node, the "exit node", is able to determine its own location in the chain.