When I use Deployment in Kubernetes, what's the differences between apps/v1beta1 and extensions/v1beta1? : <p>I use the <a href="https://raw.githubusercontent.com/kubernetes/kubernetes.github.io/master/docs/tutorials/stateless-application/deployment.yaml" rel="noreferrer">yaml file</a>, which is in the Kubernetes official document,  to create a Deployment in Kubernetes, and it uses <code>apiVersion: apps/v1beta1</code> at the top. Then I typed <code>kubectl create -f deployment.yaml</code> to create this Deployment, but it occured an error as following:   </p>

<pre>
error: error validating "deployment.yaml": error validating data: couldn't find type: v1beta1.Deployment; if you choose to ignore these errors, turn validation off with --validate=false`
</pre>

<p>After some search, I changed <code>apiVersion: apps/v1beta1</code> to <code>extensions/v1beta1</code>, and then recreate the Deployment with the yaml file, and it worked fine.<br>
So, I wanna know what's the differences between <code>apps/v1beta1</code> and <code>extensions/v1beta1</code>. Is it pertinent to the Kubernetes version?  </p>

<pre>
# kubectl version
Client Version: version.Info{Major:"1", Minor:"5", GitVersion:"v1.5.4", GitCommit:"7243c69eb523aa4377bce883e7c0dd76b84709a1", GitTreeState:"clean", BuildDate:"2017-03-07T23:53:09Z", GoVersion:"go1.7.4", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"5", GitVersion:"v1.5.4", GitCommit:"7243c69eb523aa4377bce883e7c0dd76b84709a1", GitTreeState:"clean", BuildDate:"2017-03-07T23:34:32Z", GoVersion:"go1.7.4", Compiler:"gc", Platform:"linux/amd64"}
</pre>
