Internet search engines like Google, Yahoo or Bing are like large knowledge repositories - they provide you with any information you want. But, there is a condition - you have to type right keywords. Everyone one of us knows this.
How many times have you got the right search results you expected? It can be never 100% correct, even though you thought of the keywords carefully. Here comes the accuracy of the search engines, and improving this accuracy between what you type and what results you get is of utmost importance to the search engine providers. Behind the wall, lots of text analytics are involved. What you normally type in the search box is an unstructured content and the search engine's job is to analyze, extract meta data and index it to convert the content into a structured one. The query is made upon the indexed data, after which the results are shown to you. What makes search engines different is the ability to add context, extract meta data from unstructured content, and index them so that accurate search results are shown to the extent possible.
What text analytics are involved here? Know them here: http://www.business2community.com/big-data/text-analytics-important-search-0889955#!PueWW .