What Infrastructure as Code is

Manage infrastructure like source code.

Infrastructure as Code (IaC) is the practice of defining your servers, networks, databases, and cloud resources in version-controlled text files, then letting a tool create and update the real infrastructure to match. Instead of clicking through a cloud console to make a server — a process nobody remembers and nobody can repeat exactly — you write what you want in a file, review it like code, and apply it. The infrastructure becomes reproducible, reviewable, and auditable, exactly like software.

Why it changed everything

Manual infrastructure has three chronic problems IaC solves. Reproducibility: a console-built server cannot be recreated identically, but a file can be applied a hundred times to a hundred environments. Drift and documentation: the code IS the documentation, always current, because the infrastructure is built from it. And review and audit: every change is a diff in version control, so you can see who changed what, review it before it ships, and roll back by reverting a commit. Infrastructure gains all the discipline software already had.

Provisioning vs configuration

Two related jobs fall under IaC, and it helps to separate them early. Provisioning is creating the infrastructure itself — the servers, networks, load balancers, databases (Terraform’s job). Configuration management is setting up what runs on those servers once they exist — installing packages, writing config files, starting services (Ansible’s job). Many real setups use both: Terraform builds the machine, then Ansible configures it. This course covers both, and the tools for each.