Heap and Stack Memory in Java

Heap and stack memory are both used during program execution, each serving a distinct purpose.

Stack
- Stack memory is used for method execution. Every time a method is called stack memory is used
- It stores local variable, method call and reference variable. - Every time a method start executing, it gets pushed into stack memory, and after execution, it is popped out. This follow the LIFO (Last In, First Out) approach. - Each thread has its own stack memory, which provide thread safety. - Memory is automatically cleared once the method execution is complete. - Stack memory is fast due to its simplicity and automatic cleanup.

Heap - Heap memory is used storing objects and their instance variables. - Whenever a object is created using new keyword it get stored in the heap memory.
- Heap memory is shared among all threads, so it is not thread-safe by default. - Memory in heap is managed and cleared by garbage collector. - Heap is slower than stack because of random access and garbage collection overhead.