This specification omits implementation details that are not essential to ensure interoperability: the memory layout of run-time data areas, the garbage-collection algorithm used, and any internal optimization of the Java virtual machine instructions (their translation into machine code).
This specification omits implementation details: the memory layout of run-time data areas-collection algorithm used, and any internal optimization of the Java virtual machine instructions (their translation into machine code). These implementation details are not essential to ensure interoperability. Time data areas are the garbage.