Whenever we build our applications, Initially we do not care about writing scalable or Non-SPOF (Single point of failure) Applications. But It is always a good practice to think about the Design, Scalability and Availability of your WebApp.
To Handle Scalability we have many techniques like Microservices, Deploying multiple instances using Docker and using Load Balancers.
Yes, You read it right. Containerizing your app alone is not sufficient, It needs more than that. Container Management is one of the main task. This is where Kubernetes comes, Kubernetes does automate the container management, deployment and scaling our apps in a broader way.
Containers
Containers is a kind of way to package all of your app with dependencies so that It can run the app independent of the platform. 
If it is not clear, Donβt worry you will catch up soon when you will go ahead in this Blog. 
Node:- Follow this Repo for code.
- Our Dockerfile looksβ¦