The order of websites on search engines based on the keywords entered. Example: If you typed "barber shop in Los Angeles" into Google.com, you would see a list of sites. Let's say that Manny's Barber Shop was the first site in the list. It would have a great search engine ranking. However, that search engine ranking would decline if you typed in "barber shop in California", since websites from all over the state might appear first.
When you use a search engine, such as Altavista.com or Google.com, it returns one or more pages full of links to web sites it "thinks" match the keywords you searched on. Those sites are ranked in priority order. A given web page`s placement in the results page is referred to as its search engine ranking.
The position that your website appears in the organic search results for a specific search term is your ranking for that term. SEO See search engine optimisation.