Many people use various search engines as the first port before accessing any site. Generally, search engines are programs that are designed to search for sites, based on the wording provided through multiple databases. Search engines are arguably amongst the greatest inventions of all time, probably after the internet. Imagine how it would be like without the search engines? Perusing through newspapers and magazines to single handily pick stuff, tedious indeed! Search engines have changed since earlier days. Right now we have several search engines, nonetheless the basic principle underlying all search engines are similar. Search engines work under three basic principles; crawling, indexing and retrieval.  The first step begins with crawling. Crawling involves acquiring data on a website. This step involves scanning sites to get a complete list on everything that is available. It involves the key titles, keywords, images and links to other pages.

Search engines are able to crawl websites using programs known as web crawlers. Web crawlers are capable of automatically browsing web pages whilst storing information on the same. In essence, on each web visit, the web crawler makes a copy of the webpage, copies it while adding its URL to an index. Once, the step is complete, web crawlers follow all page links, repeatedly copying and indexing the pages as it follows the links. The process progressively and continuously continues as it builds up the super huge index of multiple web pages. It is important to note, that websites that do not allow web browsers are usually left out in search engine indexes.

The information that the web crawler builds up is used by search engines as the search engines index, as such every website pages that are recommended by search engines have been visited by web crawlers. The process of indexing involves collecting data gathered from web crawlers into one massive database. The process can be compared to going through books, writing the lists in indexes, separately under different categories, such as author’s name, title, dates, but not just from one book but every library in the world! Yes, the process is not an easy one. The last step is basically what you see each time you key in into a search engine.

Normally, the search displays documents and sites that match your query. Though the process is not that easy, search retrieval is one area in which search engines distinguish themselves. Some search engines utilize keywords, while other utilizes queries. Similarly, others are more advanced including proximity keyword filtering. The ranking algorithm checks the search engine query against millions of pages whilst determining the relevance of each page. In fact, page ranking is best used to improve search results. Simply, this means that the more links that there are to a page, then the more useful the webpage will seem. This is actually a complex and competitive situation with companies acquiring patents to safeguard their ranking algorithms so as to competitively remain on top as providing the best search results.

The web page that is displayed on the first page is those that are ranked as being the best. Despite of the ranking, search engines also are keen to other signals when processing the search results. For instance, apart from Search Engine optimization that focuses on keywords, search engines are also concerned on page updates, best content and great user experience. There are several search engines in which one can choose from. Various search engines utilize different algorithms. Thus, this means that some sites will produce results that are different in order or may altogether produce different results.