Amazon Elastic Compute Cloud (EC2) is a core component of Amazon Web Services that provides scalable cloud-based computing capacity, allowing users to provision compute resources in the form of virtual servers called instances. EC2 offers a wide range of instance types with different CPU, memory, storage, and networking capacities, as well as various operating systems and software configurations. Users can monitor their instances' performance using CloudWatch's metrics, including disk I/O, network throughput, CPU utilization, and status checks. Monitoring these metrics is crucial to ensure the health and performance of EC2 infrastructure, detect potential issues, and make informed decisions about instance scaling, upgrading, or downscaling. Additionally, users need to be aware of events that may affect their instances' lifecycle, such as stopping, retiring, or system maintenance. While CloudWatch does not report system-level memory metrics for instances, users can collect memory metrics using other methods. By tracking these metrics and understanding how to interpret them, users can optimize their EC2 infrastructure to meet their needs efficiently and cost-effectively.