AWS's monitoring and observability service that collects metrics, logs, and events from AWS resources. It lets you build dashboards, alarms, and automate actions based on metrics.
On CLF-C02 this is the monitoring tool. SAA-C03 integrates it with Auto Scaling (scaling based on CPU metrics). Question: which service creates alerts when CPU exceeds 80%? CloudWatch Alarms.
Amazon CloudWatch is a concept that can show up on the exam. Check the full guide to see it in context.