Note: This term is specific to CockroachDB, a Distributed SQL database. In other contexts, it may be used differently.
When a request comes into CockroachDB, the load balancer routes the request to the node it thinks can best handle the request at that time. This node is called the Gateway Node. The Gateway Node receives the request and then responds to the request. It identifies which nodes in the cluster are the leaseholders for the specific requests that came in, and sends the requests to those nodes.