Will the stack or heap memory size change if multiple threads are created in the application?

Will change.

• Stack: When a new thread is created, a new independent stack is created for that thread. Each thread has its own stack for storing local variables, method parameters, and return addresses.
• Heap: The heap is shared among all threads in the application. Objects created in any thread using new are allocated on the heap and accessible to all threads (considering visibility and synchronization rules). Creating a new thread does not directly affect the size of the heap, but thread activity can lead to memory allocation and deallocation on the heap.

In summary: The stack size increases with each new thread, and the heap size can change depending on what objects are created and used by the threads.