In today's world, simply being able to run an image is not considered a production-ready setup.
To be able to call a deployment "production-ready," you need to be able to demonstrate that the service your application is delivering will run reasonably, even in the case of a single application crash, as well as hardware failure. Often, you'll have even more reliability constraints from your customer.
Luckily, your software is not the only data that has those requirements, so orchestration solutions have been developed for this purpose.
Today, the most successful one is Kubernetes due to its various distributions/versions, so we are going to focus on it primarily.
The idea of Kubernetes is that you inform the Kubernetes Control Plane that you want X number of instances of your Y application, and Kubernetes will count how many...