What is the Stack?

• The stack is a region of process memory used for:
• Function call bookkeeping (return addresses)
• Local variables
• Saved registers and spilled temporaries
• Passing extra function arguments
• It is a LIFO structure: Last In, First Out.
• On x86-64 the stack grows toward lower addresses.
• Two registers govern it:
• RSP — the stack pointer, always points to the top of the stack.
• RBP — the base pointer (frame pointer), a stable anchor for the current frame.