What is Wolfram Alpha?

Here’s what Wolfram Alpha does according to their website: 

“Making the world’s knowledge computable….Today’s Wolfram|Alpha is the first step in an ambitious, long-term project to make all systematic knowledge immediately computable by anyone. You enter your question or calculation, and Wolfram|Alpha uses its built-in algorithms and growing collection of data to compute the answer. “

Basically, this means W|A is not a search engine but rather an answer engine. Based on your effective searches on  W|A, an answer is created by computations.  This answer engine is also