Amazon Web Services (AWS)

AWS CloudTrail is a governance, compliance, and auditing service that records API calls and account activity across an AWS infrastructure. It captures a comprehensive event history of actions taken through the AWS Management Console, SDKs, command-line tools, and other AWS services, providing a complete audit trail of who did what, when, and from where. 

CloudTrail is fundamental for security monitoring and incident investigation in AWS environments. It detects unauthorized access, privilege escalation, resource modifications, and policy changes. The service supports multi-region and organization-wide trails, log file integrity validation, and integration with CloudWatch for real-time alerting on critical security events.