AWS — Difference between CloudWatch and CloudTrail

Comparison: CloudWatch vs CloudTrail in AWS.

TL;DR:

CloudWatch focuses on the activity of AWS services and resources, reporting on their health and performance.
CloudTrail is a log of all actions that have taken place inside your AWS environment.

CloudWatch: “What is happening on AWS?” and logging all the events for a particular service or application.
CloudTrail: “Who did what on AWS?” and the API calls to the service or resource.