Ansible is a tool that allows you to control remote servers from the comfort of your laptop.
It works over SSH and doesn't require any special software or agent to be installed on the remote machine. That doesn't sound like much. Any beginning sys admin knows how to run commands or complete shell scripts on remote servers. The power of Ansible comes from its sophisticated conceptual model and from its plugin-based module system. The combination of the two allows you to manage, configure and efficiently orchestrate hundreds, and even thousands, of servers. -