What's the difference between ingressGateways in the operator and Kind: Gateway in a separate file

1

In my operator.yaml I’ve got a few ingress gateways for various things.

spec:
  tag: 1.15.1
  profile: minimal
  components:
    ingressGateways:
...

but I’ve also got a gateway.yaml file with each entry one corresponding to the gateway in my operator.

apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: istio-gateway
  namespace: istio-system
spec:
  selector:
    istio: ingressgateway
  servers:
...

What’s the difference between these two? Are they the same thing? If so can I combine them?