What is the main purpose of Amazon CloudTrail?

The main purpose of Amazon CloudTrail is to log AWS API calls for governance and compliance. CloudTrail captures all API requests made in your AWS account, recording details such as who made the request, when it was made, the resources that were affected, and the outcomes of those requests. This logging capability is crucial for auditing purposes, enabling organizations to track changes and access across their AWS resources, which is essential for maintaining compliance with various regulatory frameworks.

By providing a comprehensive log of API activities, CloudTrail helps administrators and security professionals understand their cloud environments better, ensuring that proper governance processes are followed. This logging also assists in forensic investigations in the event of security incidents, creating a clear picture of what actions were taken in the account and by whom, thus facilitating transparency and accountability in resource management.

The other options pertain to functionalities outside of what CloudTrail specifically offers. While monitoring performance metrics, automating backups, and providing security alerts are important aspects of AWS management, they are handled by other AWS services.