CKAD (short for Certified Kubernetes Application Developer) is a program that has been developed by the Cloud Native Computing Foundation (CNCF), in collaboration with The Linux Foundation.
Kubernetes is all over the place so it does make sense to provide training & certification by the 2 organizations that are lead experts in standardizing the Cloud Native landscape. You can say that CKAD certificate is the defacto standard that is widespread and accepted by the industry.
As you might have noticed, CKAD focuses on the use of k8s for Application Developers. There is also another certificate focussing on the management aspect of k8s called: CKA, Certified Kubernetes Administrator which we will describe in another blog post.