"But Sidewalk was really aimed at what we now call local search," Mr. Ballmer says.

Many feel that Dialog led the way to the Web's search engines and what we call search today.

This specific type of search is called greedy best-first search.

People in need of assistance had to call the police, fire, ambulance and search and rescue services directly.

The new service, which Google is calling universal search, was introduced on Wednesday and will gradually become evident to users.

The brute-force method for finding an item in a table - namely, check all entries of the latter, sequentially - is called linear search.

Worth then ordered his men out on what would now be called 'search and destroy' missions during the summer.

Such systems are sometimes called infrared search and track sensors.

Last month, for instance, Google unveiled a service it calls universal search that intersperses videos, photos, news and other content into traditional search results.

This is often called visual search or simply search, to distinguish it from fast forward, when you don't see the picture.