This method involves defining your infrastructure in code and using automation to deploy it to production. This way, you can easily replicate your production environment in other environments, such as staging and development. You can also easily roll back to a previous version of your infrastructure if you need to.
This method is very important to ensure that you can test your deployment process in a lower environment before deploying to production. It also ensures that you can easily replicate your production environment in other environments. You hear a lot of cases where everything is working in staging environment but broken in production.