What is gateway bind and defaultEndpoint for?

[root@master01 gateway]# kubectl explain Gateway.spec.servers

KIND: Gateway
VERSION: networking.istio.io/v1beta1

RESOURCE: servers <Object>

DESCRIPTION:
A list of server specifications.

FIELDS:
bind

defaultEndpoint

hosts <string>
One or more hosts exposed by this gateway.

port

tls
Set of TLS related options that govern the server’s behavior.

here ,how to config bind, and defaultEndpoint ,any demos