Traffic
There are different kinds of traffic that we'll refer to later on throughout this book.
Inbound (or ingress)
Inbound traffic is the traffic that comes from outside to the cluster, towards a service running inside it. This is typically an end-user, or an external system accessing our external API's.
Internal
Internal traffic is traffic that is generated inside the cluster, and whose destination is another service within the cluster. This is typically a service to service request.
Outbound (or egress)
Outbound traffic is traffic originated inside the cluster, whose destination is somewhere outside the cluster, can be some service of our infrastructure running outside of the cluster, or a third party API that we are integrated with.