The integration of Wireless Power Transfer (WPT) and Mobile Edge Computing (MEC) has enabled the development of Wireless Powered Mobile Edge Computing (WPMEC) networks, which are considered crucial for the sustainability of Industrial Internet of Things (IIoT) systems. The primary objective of WPMEC is to enhance the computational capabilities of mobile devices while compensating for their battery limitations. A WPMEC system consists of energy transmitters, mobile devices, and edge servers, forming a closed-loop structure. Due to network dynamics, limited battery life, and the half-duplex operation of mobile devices, the simultaneous resolution of computation offloading and resource allocation challenges in WPMEC networks is highly complex. This paper provides an overview of the fundamental characteristics of WPMEC networks. The key parameters for WPMEC architecture design are analyzed, several resource allocation models are presented, and critical challenges in their implementation are identified.