## Core Concepts

### Inventory
File listing managed hosts (servers):
```ini
[webservers]
web1.example.com
web2.example.com

[databases]
db1.example.com
```

### Playbooks
YAML files describing desired state:
```yaml
- name: Install nginx
  hosts: webservers
  tasks:
    - name: Install nginx
      apt:
        name: nginx
        state: present
```

### Modules
Reusable units of work (apt, yum, copy, service, etc.)

### Roles
Organized collections of tasks, handlers, and files

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