## Variables

Define and use variables for flexibility:

```yaml
- name: Deploy application
  hosts: all
  vars:
    app_version: "2.1.0"
    app_port: 8080
  tasks:
    - name: Deploy app
      get_url:
        url: "https://example.com/app-{{ app_version }}.tar.gz"
        dest: "/opt/app"
```