* [Extensions API](/docs/api-reference/extensions/v1beta1/operations/) - Manages extensions resources such as Jobs, Ingress and HorizontalPodAutoscalers.
* [JSONPath](/docs/user-guide/jsonpath/) - Syntax guide for using [JSONPath expressions](http://goessner.net/articles/JsonPath/) with kubectl.
* [kube-apiserver](/docs/admin/kube-apiserver/) - REST API that validates and configures data for API objects such as pods, services, replication controllers.
* [kube-proxy](/docs/admin/kube-proxy/) - Can do simple TCP/UDP stream forwarding or round-robin TCP/UDP forwarding across a set of backends.
* [kube-scheduler](/docs/admin/kube-scheduler/) - A policy-rich, topology-aware, workload-specific function that significantly impacts availability, performance, and capacity.
* [kubelet](/docs/admin/kubelet/) - The primary "node agent" that runs on each node. The kubelet takes a set of PodSpecs and ensures that the described containers are running and healthy.
## Glossary
Explore the glossary of essential Kubernetes concepts. Some good starting points are the entries for [Pods](/docs/user-guide/pods/), [Nodes](/docs/user-guide/pods/), [Services](/docs/user-guide/services/), and [Replication Controllers](/docs/user-guide/replication-controller/).
## Design Docs
An archive of the design docs for Kubernetes functionality. Good starting points are [Kubernetes Architecture](https://github.com/kubernetes/kubernetes/blob/release-1.1/docs/design/architecture.md) and [Kubernetes Design Overview](https://github.com/kubernetes/kubernetes/tree/release-1.1/docs/design).