Wireless sensor network (WSN) has enormous applications in many places for monitoring the environments of importance. Sensor nodes are capable of sensing, computing, and communicating. These sensor nodes are energy constraint and operated by batteries. Since energy consumption is an important issue of WSN, there have been many energy-efficient protocols proposed for the WSN. Directed diffusion (DD) is a datacentric protocol that focuses on the energy efficiency of the networks. Since the first proposal of DD protocol by Deborah, there have been various versions of DD protocols proposed by many scientists across the globe. These upgraded versions of DD protocols add on various features to the original DD protocol such as energy, scalability, network lifetime, security, reliability, and mobility. In this paper, we discuss and classify various characteristics of themost populardirected diffusion protocols that have been proposed over couple of years.