[ellius]

Imagine you want to create some new machines. Maybe you need four servers: 2 running Ubuntu operating systems and 2 running Centos.

Traditinally, you would get four physical servers together and then manually load an operating system onto each one.

With the advent of cloud technology, you can simply go to Amazon or DigitalOcean or whoever and just "create" these resources by paying for space in their data centers. You get four "virtual servers" instead of physical boxes you have to configure yourself.

Terraform essentially lets you "code" and automate the cloud provisioning. Instead of going to a dashboard and ordering four servers, you run a script that describes all of the servers you need as well as their operating system / networking / etc. needs. This scales very well (once you have a config you can replicate it to whatever quantity you require) and also provides consistency and reliability, as well as documentation, of your infrastructure.