Search for anything using your favorite crawler-based search engine. Nearly instantly, the search engine will sort through the millions of pages it knows about and present you with ones that match your topic. The matches will even be ranked, so that the most relevant ones come first.
Now pretend you walk into your local supermarket and ask the cashier for Food. The cashier just might look at you with a Blank Face. Right? Hopefully your cashier will ask you "what kind of food are you searching for?".
Meat, Dairy, Dry Goods, Fruits? (Well you get the point right?)
So, how do crawler-based search engines go about determining which website is relevant? when confronted with hundreds of millions of web pages to sort through? They follow a simple set of rules, known as an algorithm. Exactly how a particular search engine's algorithm works is a closely-kept trade secret. However, all major search engines follow it.
Please Do not try to figure it out.
One thing we do know is:
Location, Frequency ...and more Location is one of the keys.
One of the the main rules in a ranking algorithm involves the location and frequency of keywords on a web page.
Remember the cashier in the above example? The cashier needs to find food to match your request. Makes sense? Search engines operate the same way. Pages with the search terms appearing in the HTML title tag are often assumed to be more relevant than others to the topic.
Search engines will also check to see if the search keywords appear near the top of a web page, such as in the headline or in the first few paragraphs of text. They believe that any page relevant to the topic will mention those words right from the start.
Frequency is the other major factor in how search engines determine relevancy. A search engine will check to see how often keywords appear in relation to other words in a web page. Those with a higher frequency are often regarded more relevant than the other web pages
