The Java Virtual Machine (JVM) manages application memory dynamically, yet can encounter challenges such as the `java.lang.OutOfMemoryError` due to limited memory allocation or inefficient garbage collection processes. This document explores how the JVM handles heap memory with garbage collections, focusing on metrics and logs for monitoring memory management. It highlights the Garbage-First (G1) collector, which organizes memory into regions and alternates between young and space-reclamation phases to manage memory efficiently while minimizing application pauses. Key JVM metrics and logs, such as heap usage and garbage collection activity, are crucial for identifying memory issues, while tools like Datadog help correlate these metrics with application performance for deeper insights. The text also emphasizes the importance of setting alerts to detect memory management issues and the role of Datadog in providing comprehensive visibility into Java applications, leveraging tools like JMXFetch and APM for monitoring and troubleshooting.