Web mining is the application of data mining techniques to extract knowledge from web data, i.e. web content, web structure and web usage data. Web personalization is the process of customizing the content and structure of a website for specifically needs. It involves application of data mining techniques on the contents of WWW but is not limited to it. Web site personalization can be defined as the process of customizing the content and structure of a website to the specific and individual needs of each user taking advantage of the user's navigational behavior.