What is the major difference between a vector and a stack?

Question

Both act like a stack. Both have push and pop operations.

Is the difference in some memory layouts?

Answer 1

I'm not aware of all the implementation details, but according to this, stack is a container adaptor. It makes sure the underlying container, which can be a vector, list or deque, works as a stack, i.e. only allows push and pop, and not random access.

So, a vector can work as a stack, but a stack cannot work as a vector, because you cannot insert or get an element at a random position.