When and in what cases does automatic garbage collection occur in Java?

In Java, garbage collection (GC) occurs when the virtual machine detects that certain objects in memory are no longer used by the program and have no references.

Key points:

• Objects with no references from active code are considered garbage.
• The JVM periodically runs the garbage collector to free memory by removing such objects.
• Garbage collection can occur at different times depending on the JVM implementation and current load.

For example, if a program creates many temporary objects that quickly become inaccessible, GC will run more frequently to free memory.

Thus, garbage collection is an automatic memory management process that helps prevent leaks and memory overflow without explicit programmer intervention.