An Overview of Approaches Used In Focused Crawlers

Web is a repository n where there is variety of information available provided by millions of web content providers. Numerous WebPages are added to web every day and the content keeps changing. Search engines are used to mine this information and the most important part of search engine is a web crawler also known as web spider. A web crawler basically is software that crawls or browses the WebPages in the World Wide Web. There are many types of crawlers having different methods of crawling like parallel crawler, distributed crawler, focused crawler, parallel crawler, and incremental crawler. In recent years, focused crawling has attracted considerable interest in research due to the increasing need of digital libraries and domain-specific search engines. This paper reviews different researches done in focused crawler which are also known as topic specific web crawler.