To save space, a search engine might replace it with what's called a marker. This explanation is simplified, but the point is that using markers can save a lot of disk space. The sentence retains most of its relevancy, and the extra space can be used to store more web pages. Some search engines store every word on a web page but they don't search for certain ones to save time. First it looks for all matches of the , then all matches of piano , then all matches of player .
Chances are, just looking for the last two words is enough to find relevant pages.
So to save time, the search engine excludes searching for a select number of small words. Corp. All Rights Reserved.