Basically, this code is the base for a linked list of RECT's, whatever they might be. Therefore, every single item in the list will each have the properties of a RECT.
The pointer is currently pointing to nothing. However, if you were making a linked list, it would eventually point to a new(on free store) ListElement
By the way, when thinking of linked lists, think of them as the following. Each object is created inside the previous object and the previous object is needed. So instead of being like this
head----->item 1----->item 2---->and so on
think of it as this
\ head /
\ item 1 /
\ item 2 /
When I think of them this way, it helps me out much more then of just simply considering them to be objects pointing to other objects.
I hope this helps u and good luck.