META search engines

Can someone smarter than me (anyone) explain how META search's are so fast??
A META search is a search of actual search engines right? Well how can they do it as fast as they do??

It basically works like this....you submitt a term to a meta search and it forwards that request to other search indexes and databases....so the actual meta engine is not doing much of the work....when the results are returned to the meta engine the dups are consolidated and the results are ranked by certain criteria...each engines ranking criteria is slightly different.....

Some drawbacks:
Since the meta engine is using various resources and the resources all use different methods of indexing and searching it is impossible for meta-search engines to take advantage of all the features of the individual search engines. Boolean searches can product weird results, phrases may not be supported, the amount of pages returned in far less then that of the actual search engine...usually less than 100.

Very good information!