* Pointers
  int x = 3;
  x (evaluates to 3, which is just the content of the variable)

  The following is very different:
  int *px = 3;
  here px is a pointer to the box which was the content
  px evaluates to a memory address
  *px evaluates to the content of the memory address pointed by x
  
  so what if I have some int x, and I want to get its memory address?
  px = &x;
  the "&" says that you want the address of the box x, not the content.

  summary: 
  int x = 1; <-- box that holds an int
  int *px; <-- some pointer to some box that holds an int
  px = &x; <-- &x evaluates to the address (or pointer) of x

  pointer -> content, you put a *
  content -> pointer, you put a &

* Arrays
  int vec[5] --> declares an array which can hold 5 ints
  
  What is an array? It's a _pointer_ to contiguous memory blocks
  -----------------------------------
  |a[0] | a[1] | a[2] | a[3] | a[4] |
  -----------------------------------

  What if you just did a?
  a is just a pointer to the address of the first block
  *a = a[0]
  *(a+3) = a[3]