Which AWS service is primarily used for monitoring the health of resources and applications?

Amazon CloudWatch is primarily used for monitoring the health of resources and applications within AWS. It provides a central location for collecting and tracking metrics, logging, and setting alarms based on specific thresholds. This service allows users to monitor resource utilization, application performance, and operational health by gathering data such as CPU usage, memory consumption, and disk activity for various AWS resources.

With CloudWatch, users can create dashboards that provide real-time insights into the performance and health of their applications and systems. Moreover, it enables automated responses through alarms that trigger actions like scaling resources or sending notifications when predefined conditions are met. This capability is essential for maintaining the reliability and availability of cloud-based applications.

Other services like AWS CloudTrail are focused on logging and tracking API calls for governance, compliance, and auditing. Amazon S3 is primarily a storage service for data, and AWS Config is used for assessing, auditing, and evaluating the configurations of AWS resources, rather than directly monitoring their operational health. Therefore, CloudWatch stands out as the dedicated service for health monitoring within the AWS ecosystem.