Purpose: Due to the exponential growth of internet users and internet traffic, information seekers are highly dependent upon search engines to extract relevant information. Due to the accessibility of a large amount of textual, audio, video etc. contents, the responsibility of search engines has increased. Design/methodology/approach: The search engine provides relevant information to internet users concerning to their query; based on content, link structure etc. However, it does not provide the guarantee of the correctness of the information. The performance of a search engine is highly dependent upon the ranking module. The performance of the ranking module is dependent upon the link structure of web pages, which analyse through Web structure mining (WSM) and their content, which analyses through Web content mining (WCM). Web mining plays an important role in computing the rank of web pages. Findings: In this article, web mining types, techniques, tools, algorithms and their challenges are presented. Further, it provides a critical comprehensive survey for the researchers by presenting different features of web pages, which are important to check the quality of web pages. Originality: In this work, authors presented different approaches/techniques, algorithms and evaluation approaches in previous researches and identified some critical issues in page ranking & web mining, which provide future directions for the researchers, working in the area.