struct node *llink;
struct node *rlink;
typedef node *nodep;
struct node *llink
A pointer is just a reference to a location in memory ("address"). In the case of a
node, a pointer to an instance of a
node is a reference to the location in memory where that
node instance is stored.
struct as defined, if you have an instance of a
node that resides in one memory location, it can point to two other
node instances that reside in their own memory locations (
Using a real-world tree as a metaphor, the
*rlink are pointers to left and right "branches" of a root node of a tree structure, respectively. Those pointers themselves may branch off into further and deeper left and right "subtrees".
Have a read of this introduction to binary trees.