Device‐to‐Device (D2D) communication is an important component in 5G communication technology due to the relative short‐communication range and high‐frequency reuse. In this article, we consider a specific D2D technology termed cache‐aided D2D communication or D2D caching networks, where devices can store content in their local storage and serve each other when part/all of the requested contents are available in their local storage. In the literature, researchers have shown that the gain in terms of communication load or throughput of D2D caching networks compared to the conventional cellular network is multiplicative as a function of the per‐device storage size. These fundamental results lead to a significant attention of the D2D caching network in recent years. In this article, we review some of the important results in this research area. First, we discuss D2D caching networks under a simplified channel model called
protocol model
. This can provide us some key insights of the gain achieved by D2D caching networks. In this part, we investigate both coded and uncoded delivery approaches. Second, we relax this simplified model assumption and apply more realistic physical layer channel model and Poisson Point Processes(PPPs) for the user device location distributions. This article focuses on different modeling, performance metrics, and analysis approaches of D2D caching networks.