C Functions Question:

A self-referential structure is one of the data structures which refer to the pointer to (points) to another structure of the same type. For example, a linked list is supposed to be a self-referential data structure. The next node of a node is being pointed, which is of the same struct type. For example,

typedef struct listnode {
void *data;
struct listnode *next;
} linked_list;

In the above example, the listnode is a self-referential structure – because the *next is of the type sturct listnode.