so the concept of infrastructre as code (IaC) is you basically model out your infrastructure using a templating language (JSON or YAML). you eliminate manual changes to infrastructure which will reduce errors. that template you create can be checked into source control and versioned. it's a way to gain greater repeatability and control over infrastructure

now the older IaC tools was built for a different era where cloud infrastructure was mainly static, there was a distinction between infrastructure and application, applications weren't as distributed, etc.

Pulumi is the next generation of IaC tools for modern cloud infrastructure. 1/ Instead of using JSON or YAML, you can use a real programming language. This allows you to use IDEs built for the language with code completion and things like that. You can also take advantage of unit testing frameworks for those languages. 2/ Pulumi spans all the major cloud providers and SaaS vendors which is useful because most applications these days use a variety of different providers. 3/ You can dynamically provision infrastructure directly from your application rather than calling everything from the CLI. 4/ Pulumi has a feature that enforces policy allowing stronger organizational control for compliance

let me know if that makes sense and where else i can elaborate

Though usually "with" docker containers needs a bit of a think-through.. Pulumi is generally declarative, which means that for instance if you want to run a container on kubernetes, you use the kubernetes resource provider to schedule the container

But there is also the Docker provider if you need to create containers and configure them and so on.