To understand how it is that search engines find the best results for all the different things that people search for on the internet we need to understand how they find and categorize your website.
Robots - The first step a search engine must do is create the index which will be searched. Search engines do that be sending out millions of programs which scan (crawl) web pages all over the internet and document their findings. These programs are called by many different names, such as bots, robots, or spiders.
Indexing - The next step for a search engine is to organize all of their collected information in an index, just like a library would organize its vast collection of books. The information we provide the bots is vital to the success of your index and ultimately your placement.
Algorithm - The final step which brings all of this information together is the search engine's secret algorithm. The algorithm can take a problem with numerous possible solutions and find the best possible solution out of those available. This is what separates a normal website from a successful tool for your business.