Professor Stephen Wolfram, who is the brains behind , explained that the website responds to a query by searching through databases and providing a direct answer, as well as illustrative graphs and tables.
Although its search prowess could challenge the dominance of Google, the professor is adamant that Wolfram Alpha is not a search engine as such, but a "computational knowledge engine".
The website can answer questions on topics ranging from the population of a country at a given time and the distance between two places, to the age and date of birth of politicians, or the weather in a particular place.
It offers users impressive precision compared with Google. For example, in response to the question "what is the population of London?", Wolfram Alpha gives a single answer (7.421m), whereas Google provides 28,500,500 website links.
However, the site is unable to answer general questions.
Wolfram explained: "We can only answer questions that have literally been asked before. However, if on inputting the question "what is the meaning of life?" it is pretty clear the answer is 42.
"We can look things up, but we can't figure anything new out.
"There will simply be one simple input field that gives access to a huge system, with trillions of pieces of curated data and millions of lines of algorithms."
Professor Wolfram founded Wolfram Research in Illinois in the US in 1987 to develop a computer algebra system called Mathematica.
The company now employs about 300 staff and Wolfram is its chief executive.
Woflram said: "I think it's going to be pretty exciting. A new paradigm for using computers and the web."
The service is free to use and there are plans for it to carry advertising. Plans are also in place to broaden and improve the service according to the website.
The site explains: "Wolfram Alpha, as it exists today, is just the beginning.
"We have both short and long-term plans to dramatically expand all aspects of WolframAlpha, broadening and deepening our data, our computation, our linguistics, our presentation, and more."