Rabieh Fashwall:
Hello everyone, I have a question regarding the certs, what is the main difference between CKA and CKAD? Is it worth to pursue both certs or one is enough? thanks for your help 
Edmund Kueh:
My humble advice will be: Aim for one initially…Once you have passed your first exam, then you re-assess to see if you still have the fire inside you to continue…
Dean H:
Depends what you role is and what you looking for. If you work with k8s daily I would say get all 3, otherwise just CKA & CKS.
CKA is administering a Cluster (Basic Usage, How K8s Works, etc…). Great if you go somewhere where you need to manage a KOPS/Manual Cluster.
CKAD is more focussed towards developers. More indepth focus around create pods with init containers, volume mounts, multi-container pods, probes, deployments, services etc…
CKS is more focused on Security. CKA cert is a pre-requisite. Focused on securing your Clusters (RBAC, Encrypting etcd, image scanning, auditing etc…).
I’ve done CKA and CKAD. Writing CKS early May.