What is the mesh gateway in istio?

I can not find the mesh gateway crd, such as helloworld-gateway.yaml.

What is the mesh gateway in istio? And how to understand it?

“mesh” gateway is default gateway used to refer all sidecars in the mes. Refer to gateways field description in Virtual service Istio / Virtual Service

I had read most of the references , but I can not find more details abort the mesh gateway, which is buildin.

Is the mesh gateway a resource like the gateways created by user, or just a concept ?

it is just a concept - do not have to create any gateways with that name

Thank you for the answer!