The API reference is a detailed document, available on the internet https://kubernetes.io/docs/api-reference/v1.6/; of course the API version will change in the future, v1.6 was the current one at the time of writing.
Before we make some actual calls to the api-server, it's worth knowing that kubectl also communicates with Kubernetes cluster using the API. As we mentioned earlier, you can see what REST calls are being made by the kubectl command. Looking at what's being sent to the server during the usage of kubectl is a great way to become familiar with Kubernetes API.
Before we start making actual REST calls, let's briefly see what API operations are possible.