Java Memory Area

Method Area

• A space created when the JVM starts

• A space where Class information, global variable information, and Static variable information are stored

• Runtime Constant Pool

  • A space where constants are stored, as the name suggests

• Information is shared across all threads

Heap

• A space where objects created with the new operator and dynamically created objects such as Arrays are stored

• Data stored in the Heap area is not destroyed unless processed by GC

• A space where Reference Type data is stored

• Information is shared across all threads

Stack

• A space where temporarily used data such as local variables and method parameters are stored

• Has a LIFO (Last In First Out) structure, where data that entered last exits first

• If a local variable is a Reference Type, the address value of data stored in the Heap is stored in the Stack for use

• A space where Primitive Type data is stored

• One exists per Thread

PC Register

• A space created when a Thread is created

• Registers the address of which instruction the Thread is processing

• Serves the role of storing the current position being executed by the JVM

Native Method Stack

• A space used when execution of methods written in languages other than Java (C, C++) is needed