Why do we need it?

We need kubernetes for various issues which Container based Applications are not able to resolve or will take some dedicated time to get resolved like
Auto Healing :-
Kubernetes have a concept of Replica Sets where you can create multiple replicas of a pod incase one of the pod goes down other will pick up and will replace it
SCALABILITY :- Container based application such as docker has Issues when we need to scale up the performance of the application by increasing the data This is where Kubernetes comes Handy
Load balancing :- Load balancing is also an Important feature which we can achieve through Kubernetes between multiple pods to secure memory consumption