During the last few decades, OPACs evolved considerably, moving from poor and scarcely engaging interfaces, often unable to answer both exploratory and known item searches, to more developed tools, enriched by many capabilities. (Bianchini & Guerrini, 2014)
Web 2.0 is characterized by social networking and participation on the Internet by user community involvement through tagging, blogs, or wikis, and by syndicated feeds or alerts.
During the last decade, tools have been created to provide solutions, such as the integration of searching options relating to all types of information sources.
This is the reason why reference service was of the utmost importance in Ranganathan's view; it was the main aid to help users in performing their exploratory searches in libraries.