Now the magic party can begin. An Ansible playbook is a set of commands (called tasks) that need to be executed in order, and it describes the desired state of the hosts after execution finishes. Think of a playbook as a manual that contains a set of instructions for how to change the state of an infrastructure; each instruction depends on many built-in Ansible modules to perform the tasks. For example, you may have a playbook that is used to build web applications that consist of SQL servers, to act as backend databases and nginx web servers. The playbook will have a list of tasks to perform against each group of servers, to change their states from No-Exist to Present, or to Restarted or Absent, if you want to delete the web app.
The power of having the playbook, over the ad hoc commands is that you can use it to configure and set up your infrastructure...