1, jvm memory classification is divided into blocks
Methods zones: the main storage class information has been loaded in the virtual machine, constants, static variables, the time compiler to compile the code and other data. It is a logical part of the stack, but the individual name "non-heap (Non-heap)". A number of virtual machines, virtual machine Hot Spot should be the most commonly used, due to the early Hot Spot will manage together methods and heap memory area, which is part of the memory is almost never recovered, so the method called area permanent generations. But later found a problem with this memory management scheme, Hot Spot changed the method of memory management strategy area, concepts and permanent address and the area will gradually fade out of view.