What is the difference between the role and playbook in Ansible?

In Ansible, a playbook is the main file that describes a sequence of tasks to be executed on target hosts. A playbook contains plays, where hosts, roles or tasks, variables, and other parameters are specified.

Role is a structured way to organize tasks, files, templates, and variables, allowing for reuse and division of configuration into logical blocks. A role typically contains directories such as tasks, handlers, templates, files, vars, and meta.

In simpler terms:

• A playbook describes what and where to do — the sequence of actions on hosts.
• A role is how to implement part of the configuration, a module with a set of tasks and resources that can be included in a playbook.

Example of using a role in a playbook:

- hosts: webservers
  roles:
    - nginx

Here, the playbook calls the nginx role, which contains all the necessary tasks and files for installing and configuring Nginx.