Explanation:

Amazon CloudWatch is the correct answer because it is AWS's monitoring and observability service designed to collect and track metrics, monitor log files, set alarms, and automatically react to changes in your AWS resources.

Key points about Amazon CloudWatch:

1. Metrics Collection: CloudWatch collects monitoring and operational data in the form of logs, metrics, and events from AWS resources like EC2 instances, RDS databases, and many other AWS services.

2. Types of Metrics: It monitors metrics such as:

   • CPU utilization for EC2 instances
   • Database connections and latency for RDS
   • Disk I/O operations
   • Network traffic
   • Memory usage
   • Request counts and error rates

3. Comparison with other options:

   • AWS CloudTrail: Records API calls and user activity for auditing and compliance purposes, not operational metrics.
   • AWS Config: Monitors and records configuration changes to AWS resources for compliance and security analysis.
   • AWS Trusted Advisor: Provides recommendations to optimize AWS infrastructure for cost, performance, security, and fault tolerance.

4. Use Cases: CloudWatch is essential for:

   • Performance monitoring
   • Resource optimization
   • Operational health
   • Troubleshooting
   • Setting up automated responses to metric thresholds

Therefore, Amazon CloudWatch is specifically designed for monitoring operational metrics like CPU utilization, latency, and disk I/O across AWS services.