What is AWS CloudWatch and what are its main components?

CloudWatch is AWS’s native observability service with four main areas:

• Metrics: Time-series data from AWS services (CPU, NetworkIn, etc.) and custom metrics you publish.
• Logs: CloudWatch Logs for storing, searching, and analyzing log data from EC2, Lambda, ECS, etc.
• Alarms: Alerts triggered when metrics exceed thresholds. Can trigger SNS, Auto Scaling, Lambda.
• Dashboards: Visual widgets to display metrics across services in real-time.

For advanced analytics, ship logs to OpenSearch (ELK) or use CloudWatch Logs Insights for SQL-like queries.