Abstract:

With the increase of  Web information, search engines have become the principal approach to information retrieval. The accessing of a page is basically decided by its ranking in search engines. Some sites boost their page ranking without improving the quality of the pages, but deceive the search engines according to its characteristic, which is called Web Spam. Web spam is one of the challenges of search engines. Valid anti-spam techniques are presented with an introduction of common Web spam.

Key words:  web spam; anti-spam; search engine