Amazon CloudWatch is a monitoring service for AWS cloud resources and the applications you run on AWS. You can use CloudWatch to collect and track metrics, collect and monitor log files, and set alarms. CloudWatch can monitor AWS resources such as Amazon EC2 instances, DynamoDB tables, and RDS DB instances, as well as custom metrics generated by your applications and services, and any log files your applications generate. You can use CloudWatch to gain system-wide visibility into resource utilization, application performance, and operational health. You can use these insights to react and keep your application running smoothly.