Chapter Five Web Search Engines Information Technology Department Bryar Hassan (BSc & MSc Eng.) bryar.hassan@kissr.edu.krd

Contents What is a Search Engine Need of Search Engine How Search Engine Works? Types of Search Engines Web Crawler SEO – Search Engine Optimization Internet Technology – First Year

What is a Search Engine A search engine is a searchable database which collects information on web pages from the Internet. Indexes the information and then stores the result in a huge database where it can be quickly searched. The search engine provides an interface to search the database. When you enter a keyword into the search engine, the search engine will look through the billions of web pages to help you find the ones that you are looking for. Internet Technology – First Year

Examples of Search Engines Internet Technology – First Year

Need of Search Engine Variety: An Internet search can generate a variety of sources for information. This variety allows anyone searching for information to choose the types of sources they would like to use, or to use a variety of sources to gain a greater understanding of a subject. Organization: Internet search engines help to organize the Internet and individual websites. Precision: Search engines do have the ability to provide refined or more precise results. Internet Technology – First Year

Searching for a keyword Searching for the keyword “thapar university” @ google Internet Technology – First Year

How Search Engine Works? A Search engine has three parts: Spider: Deploys a robot program called a spider or robot designed to track down web pages. It follows the links these pages contain, and add information to search engines’ database. Example: Googlebot (Google’s robot program) Index: Database containing a copy of each Web page gathered by the spider. Search engine software: Technology that enables users to query the index and that returns results in a schematic order. Internet Technology – First Year

How Search Engine Works? Internet Technology – First Year

Types of Search Engines Text Search Engines General: AltaVista, Ask Jeeves, Bing, Google Specialized: Google Scholar, Scirus, Citeseer Image Search Engines - How can we search on the Image content Video Search Engines - Image Search with Time dimension Crawler Powered Indexes - google.com Human Powered Indexes Hybrid Models - Submitted URLs to a search engine Semantic Indexes - Semantic search seeks to improve search accuracy by understanding the searcher's intent and the contextual meaning of terms as they appear in the searchable dataspace, whether on the Web or within a closed system, to generate more relevant results. Internet Technology – First Year

Web Crawler A Web crawler is a computer program that browses the World Wide Web in a methodical, auto mated manner. Other names Crawler Spider Robot (or bot) Web agent Wanderer, worm Examples: googlebot, msnbot, etc. - Crawler: a program that systematically browses the World Wide Web in order to create an index of data. Internet Technology – First Year

Web Crawler Architecture Internet Technology – First Year

Application of Crawling Concept Search Engine Optimization (SEO) is the process of affecting the visibility of a website or a web page in a search engine's unpaid results, often referred to as "natural," "organic," or "earned" results. Internet Technology – First Year

SEO – Search Engine Optimization Internet Technology – First Year