Search Engines Essay, Research Paper
A search engine is an online service that can aid a user in finding a web page that contains particular content the user is looking for. There are many different search engine services on the web. They are primarily distinguished from each other by the way they gather their information. Searching these engines only requires a small text command, and there are many ways to narrow down your searches. For instance, Boolean operators and phrase searching.
If a Webmaster does not get his/her web page listed on a search engine automatically, then they might choose to suggest their page to the search engine themselves.
A Meta tag is a small piece html code used by a website to control what a search engine categorises and stores the site as in their database. It basically tells the search engine what you want your page listed as.
Search engines are used by millions of people around the world on a daily basis. They are the easiest and most user-friendly way to find content on the Internet. They provide an invaluable service to the Internet user by providing a huge database of websites that the user can quickly search through. Keywords a user enters into the search box are matched to resources in the search engine’s database that contain the keywords. These are then sorted by their relevance and presented to the user with the most relevant sites appearing first. The size of the different search engines databases can vary greatly, as all of the different types of engine don t gather data the same way.
Search engines use special indexing software, called robots or spiders, to gather their information. These programs are made to constantly “crawl” the Internet in search of new or updated web pages. They will go through every URL until they have visited every Web site on the Internet.
When visiting a web site a robot or spider will record all of the text on the main page, then, depending on the search engine, every page within the web site. It will then access all of the links on the website. This is how search engines are able to find a user s site regardless of whether or not they register their URL with the search engine. Submitting an URL however gets the user on the database a lot faster. It notifies a crawler to visit and index the user s site instead of waiting for it to eventually find it through one of the external links.
Robots will revisit the site periodically to refresh the page s information. This allows the search engine to automatically find dead links , or pages that are no longer there. The robot will try unsuccessfully to update the information on a dead link and realize it isn t there.
One of the things that separate all of the different search engines is how they are organized and what they include in their databases when crawling . Some engines only record the contents of the main page of a site, where others record all pages in a site, effectively recording every page on the Internet.
Also unique are the criteria different search engines use to organize information for its users. Some use a system known as link popularity, listing the results of a user’s search according to which sites have the most links from other sites. Other search engines sort results according to the summary information in a site s Meta tags, and others look for common themes used throughout a site. There are many other ways to organise results, and the leading search engines use a combination of several of them.
There is a different sort of content database on the Internet, very similar to a search engine. This is called a directory. The main difference between a search engine and a directory is that a directory will not list an URL if it has not been manually registered with them. They do not use indexing software and so have no way of knowing of content that is not introduced to them. This is the main difference with search engines. Directories on the most part add content after they review it, sacrificing a lot of quantity for quality of site descriptions and organisation. Directories are usually subdivided into categories so when a user submits their URL, they have to submit it under an appropriate heading.
Leading search engines such as Yahoo use a hybrid system, utilizing directory and search engine functions at the same time.
Meta tags consist of a small piece of HTML code included in a web page used to control the websites description in a search engine. A Meta tag included in a web page basically tells the search engine robot how it wants the site described and indexed. They can help improve the position that a user s website is placed at when a search is made for the website s content. The main aim for a Webmaster is to have their page displayed first when a search is entered in their subject, making more people notice the site.
With so many pages listed in a search engine database it still can be hard to find a particular site just by using keywords. This is remedied by the addition of powerful commands and expressions that can be added to a search request to help decrease the amount of sites to be displayed. One of these methods is the phrase search. This incorporates quotation marks to link the words enclosed in them. If a user were to enter the search Chocolate Cookies, without quotation marks, the search engine would look for sites containing both of the words, sites containing the word cookies and sites containing the word chocolate. The Internet being what it is would most likely come up with about five hundred thousand topics, ranging from Internet cookies to pornographic material. If, however, the two words were enclosed in quotation marks, the results would be reduced drastically as the engine only displays the sites containing both the words in succession.
Another command that is available is the Boolean operator. This expression allows the user to add and subtract words and phrases in the search. For example if most of the web sites were about chocolate chip cookies, when you want only plain chocolate cookies, you can write:
Chocolate Cookies NOT chip
If the results were showing a lot of cookie manufacturers, but recipes were required, then the following expression can be used:
Chocolate Cookies AND recipes NOT chip
Most likely this will come up with a majority of recipes about plain chocolate cookies, as the engine will only display sites with the subject of chocolate cookie recipes, and will not display anything about chips, eliminating the chocolate chip cookie problem.
These commands help to make a search engine a powerful and resourceful service.