02.13.08
How Search Engines Work
How Search Engines Work
Search engines need to use very advanced systems if they want to be able to return web results that are relevant, and which will effectively answer the needs of those who use the Internet to find information. If you are wondering just what makes these search engines tick and make them provide you with the results that you see each time you enter a search term or keywords, then the following information should help provide you with a good idea about how search engines work.
Spiders that crawl the World Wide Web
The first thing that you would need to understand when it concerns learning about the behind-the-scene going-on of search engines is what is a spider and why does it crawl the entire web looking for relevant information. Spiders are specialized programs that automatically look at content present on the web and they make use of the way that the web is structured with regard to hyperlinks and thus are able to easily crawl about eight to ten billion pages as well as documents that are part (actually, half) of the entire World Wide Web’s content.
Indexing documents
Secondly, there is another method that helps search engines locate useful content and that is by indexing documents. Once the spider finds material through its crawling activities, the search engines then makes an index of the documents, which in simple terms means that that the pages of content are stored in database (homogenous) of documents that then form the ‘index’ of the particular search engine. However, such indexes need to be managed with absolute precision and there is certainly no place for errors since the search engine has to crawl billions of documents and do so in just a few seconds.
Different ways of entering search queries
Internet surfers are always querying the search engines and each time that they do so, the search engine has to go to its index and from there retrieve the relevant documents that are pertinent to the search term or keywords entered. However, the search engine results are greatly influenced by the manner in which surfers make their queries that search engines use to do their searching. Thus, if you enter your query enclosed in quotes, you would not find the same results as when you don’t use quotes and the reason is that the search engine looks for the exact phrase when quotes are present and when they are absent, it returns any and all of the words used in the query.
Most relevant results are ranked the highest
Each search engine has its own algorithm with which to do the searching and in addition there are very precise calculations made on the results themselves in order to rank them according to their relevance to the search query. Thus, the results that match user’s search queries the best are ranked highest while those that are not such close matches are ranked further down, and this ranking helps the users to make a start with the results sure of finding most relevant results at the top of the search engine results pages.