This page standardizes the core terms used across the docs.

Term Meaning
Listener A downstream ingress socket and TLS identity definition. A listener owns an address, port, protocol, and certificate set.
Bootstrap TLS listener The compatibility ingress path used for downstream HTTP/1.1 and HTTP/2 on the listener address/port.
Upstream A named routing target consisting of route rules, optional TLS policy, load-balancing policy, and one or more backends.
Backend A single origin endpoint inside an upstream pool.
Route The match conditions that decide which upstream handles a request.
Control API The privileged operator-facing admin HTTP surface.
Metrics endpoint The Prometheus exposition endpoint.
Drain The process of stopping new admissions while allowing existing work to complete or time out.
Cert reload Reloading listener certificate material for new handshakes only. This is not full config reload.