Tell me about how the Garbage Collector works in Java.

Garbage Collector (GC) in Java is an automatic memory management mechanism that frees memory occupied by objects that are no longer referenced in the program.

Main features of GC operation:

• Heap is divided into generations: Young Generation, Old Generation, and sometimes Permanent Generation (PermGen) or Metaspace (in newer JVM versions).
• Young Generation contains recently created objects. A common algorithm used here is copying, where live objects are copied to another area, and the remaining memory is freed.
• Old Generation contains objects that have survived several GC cycles in the young generation. More complex algorithms like Mark-Sweep or Mark-Compact are used here.
• GC is triggered when free memory in the heap runs out. JVM can use different types of collectors (Serial, Parallel, CMS, G1, etc.) depending on settings and version.
• Garbage collection pauses can affect performance, so modern collectors aim to minimize their duration and frequency.

Example of G1 GC configuration in JVM:

java -XX:+UseG1GC -Xms512m -Xmx2g MyApp

Thus, GC relieves the programmer from manually managing memory, reducing the risk of leaks and errors.