South Asian Journal of Engineering and Technology Vol.2, No.21 (2016) 21 – 27 Evolution of Search Engines: An Aerial View T.Prakash , V.Ashok kumar*, M.Jayaprakash DLIS, Periyar University, Salem *Corresponding Author: T.Prakash E-mail: [email protected] Received: 02/11/2015, Revised: 14/12/2015 and Accepted: 11/03/2016 Abstract This paper aim to the scope of Search engines and it‘s are among the most useful and popular services on the Web.we describe an overview of next generation, new search engines standardized, statistical way of measuring search engine coverage and overlap through random queries. To make the use of an idea of search and browsing of the user to be easiest search and access. And describes about the various types of search engines and it uses. Click here to enter text. Keywords: Search Engines, WWW, types. *Reviewed by ICETSET'16 organizing committee 1. Introduction Today it is estimated that the worldwide, search engines plays a vital role in retrieving in function with specific theme on which the user attempt to work on. In spite of the various search engines locating the exact information is often a hit or a mass proposition. His technology underlying text search engines has advanced dramatically in the past decade. The development of a family of new index representations has led to a wide range of innovations in index storage, index construction, and query evaluation. While some of these developments have been consolidated in textbooks, many specific techniques are not widely known or the textbook descriptions are out of date. In this tutorial, we introduce the key techniques in the area, describing both a core implementation and how the core can be enhanced through a range of extensions. We conclude with a comprehensive bibliography of text indexing literature. 2. Search Engines A web search engine is a software system that is designed to search for information on the World Wide Web. The search results are generally presented in a line of results often referred to as Search Engine Results Pages (SERPs). The information may be a specialist in web pages, images, information and other types of files. Some search engines also mine data available in databases or open directories. Unlike web directories, which are maintained only by human editors, search engines also maintain real-time information by running an algorithm on a web crawler. 21 South Asian Journal of Engineering and Technology Vol.2, No.21 (2016) 21 – 27 Search engines searches the web, it allows users to enter search terms- keywords / phrases, retrieves information and web pages from its database that match the search terms entered by searcher. They run from special sites on the web and are designed to help peoples find information stored on other sites. They differ from in their search speed the design of the search interface, in which they display the search results the amount of help available and so on. They are known by names ―Internet Search Engines‖ or ―Web Search Engines‖ Web search engines work by storing information about many web pages, which they retrieve from the page's HTML. These pages are retrieved by a Web crawler (sometimes also known as a spider) — an automated Web browser which follows every link on the site. The site owner can make exclusions by using robots.txt. The contents of each page are then analyzed to determine how it should be indexed (for example, words can be extracted from the titles, page content, headings, or special fields called Meta tags). Data about web pages are stored in an index database for use in later queries. A query from a user can be a single word. The index helps find information relating to the query as quickly as possible. Some search engines, such as Google, store all or part of the source page (referred to as a cache) as well as information about the web pages, whereas others, such as AltaVista, store every word of every page they find. This cached page always holds the actual search text since it is the one that was actually indexed, so it can be very useful when the content of the current page has been updated and the search terms are no longer in it. This problem might be considered a mild form of link rot, and Google's handling of it increases usability by satisfying user expectations that the search terms will be on the returned webpage. This satisfies the principle of least astonishment, since the user normally expects that the search terms will be on the returned pages. Increased search relevance makes these cached pages very useful as they may contain data that may no longer be available elsewhere. 2.1 Search Engine Bias Although search engines are programmed to rank websites based on their popularity and relevancy, empirical studies indicate various political, economic, and social biases in the information they provide. These biases can be a direct result of economic and commercial processes, and political processes. 2.2 Types of Search Engines There are several types of search engines are using worldwide. 1. Crawler-Based Search Engines: Crawler-based search engines use automated software programs to survey and categorise web pages. The programs used by the search engines to access your web pages are called ‗spiders‘, ‗crawlers‘, ‗robots‘ or ‗bots‘. Examples of crawler-based search engines are: Google, Ask Jeeves 2. Directories: A ‗directory‘ uses human editors who decide what category the site belongs to; they place websites within specific categories in the ‗directories‘ database. There are two major directories at the time of writing: Yahoo Directory, Open Directory 3. Hybrid Search Engines: Hybrid search engines use a combination of both crawler-based results and directory results. More and more search engines these days are moving to a hybrid-based model. Examples of hybrid search 22 South Asian Journal of Engineering and Technology Vol.2, No.21 (2016) 21 – 27 engines are: Yahoo, Google. 4. Meta search engines: Meta search engines take the results from all the other search engines results, and combine them into one large listing. Examples of Meta search engines include: Meta crawler, Dogpile 5. Specialty Search Engines: Specialty search engines have been developed to cater for the demands of niche areas. There are many specialty search engines, including: Local Search, Domain Search Name, Freeware and Shareware search. We aim to provide you with the most up-to-date search engine list on the Internet today. We‘re continuously adding new ones as they make our top ten lists, then removing defunct or downgraded websites as necessary. On this site you will find a comprehensive list of the top multipurpose search engines as well as industry- specific ones. 1. Ask 2. Blekko 3. DuckDuckGo 4. SrubTheWeb 5. Entireweb 6. Gigablast 2.3 News Search Engines 1. NewsIndex 2. InfoGrid 3. DrudgeReport 4. Topix 5. DayLife 6. HeadlineSpot 7. Google 8. youdao 9. sogou 10. yandex 11. yahoo 12. HotBot 2.4 Book Search Engines A comprehensive list of search engines that allow readers to find books, guides and search for related products, services and information online. Some of the web sites listed here only return items that were posted to them specifically, while others aggregate them from various places and display it in one central location. Booksellers can also use many of these websites to submit their available inventory for sale on the Internet. 1. Amazon 23 South Asian Journal of Engineering and Technology Vol.2, No.21 (2016) 21 – 27 2. ebay 3. barnesandnoble 4. abebooks 5. alibris 6. powells 7. bookfinder 8. biblio 9. feedbooks 10. shopclues 2.5 Jobs Search Engines A comprehensive list of search engines that allow career seekers to find jobs, post resumes, and search for other employment opportunities online. Some of the web sites listed here only return positions that were posted specifically to each respective web site, while others aggregate them from various other places and display it in one central location. Employers can also use many these sites to list available openings at their company 1. craigslist 2. indeed 3. monster 4. careerbuilder 5. simplyhired 6. theladders 7. naukri 8. shine 9. freshers voice 2.6 Kids Search Engines A comprehensive list of search engines those are family-friendly and safer for kids to use. Most of these are informational web sites geared towards children, covering a variety of topics to help them research and learn. Some of them only show resources from their own database, while others aggregate content from multiple other places into a central location. Students can use these websites to research for their homework for a number of popular subjects online. 1. Infoplease 2. AOL Kids only 3. Kidsclick 4. Factmoster 5. Askkids 6. kidskonnect 24 South Asian Journal of Engineering and Technology Vol.2, No.21 (2016) 21 – 27 2.7 Social Search Engines A comprehensive list of search engines that allow users to find real-time information, products and services shared by people from all over the world. Some of the web sites listed here only return content that was posted to them specifically, while others aggregate data from various other resources and display it in one central location. Businesses can also use many of these websites to promote their company by sharing important messages with customers, and automatically posting content through the use of RSS feeds. 1. twitter 2. friendfeed 3. topsy 4. socialmention 5. pubsub 6. wikio 7. Google plus 8. eurekster 9. facebook 10. tumblr 2.8 People Search Engines A comprehensive list of search engines that allow users to look for people in various different ways, including by first and last name, a person‘s phone number, address, social security number, employment history and others.