Take a Better Look At Search Engines |
| Date Added: April 21, 2010 12:23:58 PM |
| Author: nactalia716 |
| Category: Computers and Internet: Search Engine Optimization |
| An Internet search engine is a software programme designed to search for information on the Web. The search results are usually called hits and are presented in the form of a list. The information may contain web pages, images, data and other types of files. Some search engines also collect data available in databanks or open directories. If compared to Web directories which are maintained by human editors, search engines function algorithmically or are a mix of algorithmic and human input. Internet search engines function by storing data about a huge number of web pages which they retrieve from the INTERNET. These pages are retrieved by An Internet crawler, also known as a spider. It is an automatically-controlled Web browser that follows every link it sees. The content of each page is then analyzed to decide how it should be indexed. Words, for instance, are extracted from titles, headings or special fields called meta tags. Data about web pages are saved and stored in an index databank for further use in queries. Some search tools, such as Google, store the entire or part of the source page (known as a cache) as well as data about web pages, while others, such as AltaVista, save and store every word of every page they have found. This cached page always contains the initial search text, since it is the one that was actually indexed. So, it can be very helpful as it includes data that can no longer be found anywhere else on the Internet. When a web user types key words in the search field, the engine checks its catalogue and displays a list of the most suitable web pages in accordance with its criteria, commonly with a short summary coupled with the title of the document and at times parts of the text. Some search engines offer an advanced tool called proximity search that allows users to determine the distance between search words. The relevance of the result set determines the usefulness of a search engine. Since there may be millions of web pages that comprise a particular search term or phrase, some pages may appear to be more relevant and popular than others. The results can be ranked to display the "best" ones first. The way a search engine ranks web pages is specific to a search engine. The methods also alter with time, as the use of Internet services changes and new techniques emerge. |
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