This book is a collection of tutorial notes and sample codes written by the author while he was learning JVM GC (Garbage Collection) processes. Topics include Java Garbage Collectors, STW (Stop-The-World), Serial Collector, Parallel Collector, Concurrent Collector, G1 Collector, GC Algorithms, Generational GC, Regional GC, Heap Memory Management, Young/New Generation, Tenured/Old Generation, Object Reference, Eden Space, Survivor Spaces, Minor GC, Major GC, Full GC, Performance Tuning, Throughput/Latency Performance, Heap Footprint.Updated in 2019 (Version 1.10) with Java 12.