CloudWatch in AWS is a monitoring and management tool that helps to monitor your applications that run on AWS. CloudWatch is used to monitor Amazon EC2, and other AWS resources like Amazon DynamoDB tables, Amazon EBS volumes, Amazon RDS DB instances, Amazon Elastic MapReduce job flows, Elastic Load Balancers, Amazon SQS queues, Amazon SNS topics.
Cloud Watch is used to monitor custom metrics, monitor and store logs, set alarms, monitor, and react to resource changes.
You can register for this AWS Migration Certification course by Intellipaat if you want to learn AWS data migration.
Also, watch this video on Amazon CloudWatch: