The publish/subscribe model is receiving growing attention in recent years. This has attracted intense efforts from the research community in the quest to obtain “internet-wide” scalability. Publish/subscribe model claimed to dynamically routes and delivers events from sources to interested users, and has the ability to disseminate information to users when it is not clear in advance which user that needs what information. In this interaction model, Subscribers have the ability to express their interest in an event or a pattern of events and are then notified of any event, generated by a publisher, which matches their registered interest. An event is asynchronously propagated to all subscribers that registered interest in that given event. In recent days, many variants of the paradigm have recently been proposed, each variant being specifically adapted to some given application or network model. However, because of the multiplicity of these systems and prototypes, it is difficult to capture their commonalities and draw sharp lines between their main variations. In this paper, we factor out the common denominator underlying these variants, these decoupling dimensions are illustrated by presenting the publish/subscribe paradigm with traditional interaction paradigms. Second, we present the many variants of publish/subscribe schemes: namely. Topic-based or list-based, content-based and broadcast based. Third, In particular, their respective benefits and shortcomings are discussed in terms of securities and implementations.