Heap: Regions located in kernel space from which memory blocks can be allocated and deallocated dynamically.
Stack : Stack is an area of memory for keeping temporary data.it uses LIFO algorithm.
Find below the differences b/w stack and heap
- local variables (variables declared inside a function) are put on the stack - unless they are also declared as 'static' or 'register'
- function parameters are allocated on the stack
- local variables that are declared on the stack are not automatically initialized by the system so they usually have garbage in them until you set them
- variables on the stack disappear when the function exits (thus, if a function is called multiple times, it's local variables and parameters are recreated and destroyed each time the function is called end exited).
- declared variables (as opposed to dynamically created ie new, malloc) are created on the heap before program execution begins, they exist the entire life of the program (although scope may prevent access to them - they still exist) and they are initialized to all zeros
- global variables are on the heap
- static local variables are on the heap (this is how they keep their value between function calls)
- memory allocated by new, malloc and calloc are on the heap