With the rise of the Internet, search engines have become a way of life for millions of computer users worldwide. Search engines allow computer users to find information and websites that have relevant answers to their questions by using keywords and meta data to match consumers with their interests. Although nearly everyone uses search engines on a daily basis, not that many people know how search engines work. In this article, we will explore types of search engines and how they operate.
What is a Search Engine
A search engine is an index of websites that uses search algorithms and predetermined rules to match consumers with their interests. When you use a search engine, all you have to do is type in a keyword or a series of keywords and the search engine will display a number of websites that contain those keywords in the correct context. Many search engines not only display websites but also images, videos, news, and documents depending on what you are trying to find. While search engines often display millions of results for your keywords, you can usually find what you are looking for by browsing through the first few results.
Crawlers
A crawler-based search engine such as Google, Yahoo, or Ask Jeeves automatically “crawls” through websites, images, videos, and documents and indexes them so that people can find them by performing a simple keyword search. Crawlers are the most popular form of search engines and allow you to find the most relevant and updated information according to your keyword search. While a crawler may not find every webpage that you might be interested in, they do index thousands of webpages every day and rescan them often.
Directories
A directory is another type of search engine that is controlled by actual people rather than an automatic system. Directories contain sources of information that other users have seen and added to the list so that others may find the information without having to stumble upon it on their own. Directories often contain descriptions about the website, image, video, or document in question and some directories even allow for users to comment the media so that other users can not only see what the information is about but also whether other people found it relevant and helpful or not. While directories are more personal and contain real human information, they do lack the capabilities that allow search engines to process large amounts of webpages.
Hybrid Search Engines
Hybrid search engines are search engines that combine both human-controlled directories with the powerful search algorithms that control crawler systems. Hybrid search engines often display results from both types of indexes and allow for users to receive more appropriate and direct responses. With a hybrid system, a user can perform a standard keyword search but then browse through a directory of comments and resources plus an automated search of popular websites that contain the information that you are seeking.
Search Algorithm
Although I’ve used the phrase several times throughout this article, I have yet to really explain what exactly a search algorithm is. A search algorithm is a set of predetermined rules that control how a search engine works. For example, a search algorithm may contain instructions on how to display results based not only on the keywords entered but also in what order the keywords were entered. Many search engines also have methods to allow the user to customized their results. For instance, Google allows users to type keywords in quotation marks in order to find webpages with that specific phrase or sentence. This type of search algorithm allows for search engines to display the most relevant information.
Sponsored Listings
Almost every search engine has a section at the top of their search results that is usually labelled as “sponsored listings”, “sponsored links”, “premium results”, or a similar title. This section does not contain more relevant information but instead contains webpages that someone has paid to have placed there. Companies and organizations often do this in order for people to see their website every time a specific or general keyword is entered. Not every search has a sponsored listing as not every keyword has someone willing to pay for it. For example, if you type “search engine” into Google, there will be no sponsored listings. However, if you type in a more business-related keyword such as “data integration”, you will see three sponsored listings at the top of the page in a yellow box labelled as “Sponsored Links”. These listings are not in any specific order and if you refresh the page, the sponsored listings may change or be put in a different order.
