AWS CloudWatchs vs. CloudTrail - What's the Difference?

This article explains the differences and primary use cases for AWS CloudWatch and AWS CloudTrail: CloudWatch is presented as a monitoring service for performance, logs, metrics, events, and alarms to optimize and scale applications, while CloudTrail is described as an auditing service that records API activity, who performed actions, and when for compliance and forensics, and the author notes they can be used together.