Microservices architecture and containers are now widely used in developing and deploying cloud-native apps. The use of container orchestrators like Kubernetes is skyrocketing. So, moving network functions to containers seems to be a logical step forward in the evolution of network architecture. Cloud-native Network Functions (CNFs) was the term coined for this technology. Basically, CNFs are network functions like routers or firewalls moved inside Linux containers, which are themselves orchestrated by tools such as Kubernetes. This means that, in a sense, Kubernetes is managing network traffic.
Some common networking terms clearly explained