AWS CloudTrail is an AWS auditing and logging service that records all API calls and account activities in your AWS environment. It helps track who performed an action, what action was taken, and when it happened.
With AWS CloudTrail, you can monitor activities such as creating EC2 instances, deleting S3 buckets, changing IAM policies, or modifying VPC settings. The logs can be stored in Amazon S3 and analyzed for security, compliance, and troubleshooting.
In simple words, AWS CloudTrail keeps a history of all activities in your AWS account, helping you audit changes and improve security.