In breadth first search of a search tree, one prgresses by first of all looking at all of the nodes at level 1 (one step form the root), then all the nodes at level 2, etc.
Defined on page 63
Used on pages 63, 65, 67, 68, 69, 70, 72, 74, 78, 80, 228, 347
Also known as breadth first, breadth first
Breadth first search -- order of visiting nodes