WolframAlpha is an computational knowledge engine. It is fundamentally new paradigm for getting knowledge and answers. Wolfram alpha does dynamic computations based on the collection of built in data, algorithms and methods. You can enter anything you want to calclulate or you can know how the calculations are done by step by step process.
Wolfram Alpha actually gives you access to the world’s facts and data na also calculates answers across a range of topics, that includes science, history, engineering, mathenatics and more.