Excerpt:
Erdös numbers have been a part of the folklore of mathematicians throughout the world for many years. For an introduction to our project, a description of what Erdös numbers are, what they can be used for, who cares, and so on, choose the “What’s It All About?” link below. To find out who Paul Erdös is, look at this biography at the MacTutor History of Mathematics Archive, or choose the “Information about Paul Erdös” link below.