search engine optimization - search engine ranking - search engine placement

SEARCH ENGINES - Why 

At last count, there were one...two...three... a lot of search engines on the Internet. Why? Do you really need that many search engines? At any given point, you only need to find one thing. So why would you need a dozen search engines to find it? You don’t. But sites get developed as a result of customer demand. Search engines are popular, so it’s no surprise that there’s a surge in them. Also, there’s no standardization to search engines. No indexes, no Dewey Decimal System. So as each new search engine pops up, each one thinks it's got the perfect methodology for finding what you need. Which one's right for you?

Though the term "search engine" is used for most search tools on the Internet, not all search engines behave the same. Knowing the difference will help you in your quest.

Search Engines
Use search engines when you know exactly what you want. Simply type the key words in the search engine's dialog box.

When you type in a search term, your computer doesn't actually go out and search the entire Internet. What happens is you actually end up searching computers that have already searched the Internet. Before you ever enter your search term, the search engine's computers automatically roam the Internet and index all the content on the Web.