Ingress controller can help you save money on your load balancers while running on public cloud providers.
A single load balancer can be used to forward traffic captured from the internet to the ingress control system
The ingress controller can be configured to route the different traffic to all your apps based on HTTP rules (host and prefixes). This only works for HTTP(S) based applications
If you're using external DNS, the appropriate DNS records will be created on your external DNS server automatically. such as Route53
It will generate a new record to route traffic to your load balancer for each hostname used in ingress.