Heap

• JVM has a heap area, which is shared across all the JVM threads.
• Heap is used to dynamically allocate memory for the class objects and arrays.
• Memory allocated by the obejcts is reclaimed by the Garbage Collector.
• Garbage Collector technique is not fixex, It is getting decided based on the requirements of the System implemantation.
• The heap area can be of fixed size, or it can be enlarged based on the computation.
• The heap memory area is not required to be contiguous. 
• If required heap memory cannot be made available by the automatic storage management of JVM then JVM will give you OutOfMemoryError.