From the website: "Wolfram|Alpha..... introduces a fundamentally new way to get knowledge and answers— not by searching the web, but by doing dynamic computations based on a vast collection of built-in data, algorithms, and methods."

.The Wolfram Functions Site ...contains the world's most encyclopedic collection of information about mathematical functions. The site also details the interrelationships between the special functions of mathematical physics and the elementary functions of mathematical analysis as well as the interrelationships between the functions in each group.