Explain the GitOps principles and how Argo CD implements them.

GitOps is based on four core principles:

1. Declarative: The entire system is described declaratively using YAML manifests
2. Versioned and Immutable: All changes are tracked in Git with complete version history
3. Pulled Automatically: Changes are automatically pulled and applied to the target environment
4. Continuously Reconciled: The system continuously ensures actual state matches desired state

Argo CD implements these principles by:

• Using Git repositories as the single source of truth for application configurations
• Continuously polling Git repositories for changes
• Automatically detecting configuration drift and providing options to sync
• Maintaining an audit trail through Git commit history
• Supporting rollbacks through Git reverts