The chapter furnishes a comprehensive overview of 5G networks, including the security considerations and challenges. The 5G core network architecture, standardized by 3GPP, is designed to meet the demands for increased throughput, reduced latency, and enhanced reliability required by various applications and services. The 5G core features a cloud-based, service-oriented architecture (SBA) that consolidates all 5G functions. This includes security, authentication, end-to-end device communication, and session management. Emphasizing Network Functions Virtualization (NFV) as a core design concept, the 5G core leverages virtualized software functions-deployable within the network. 5G technology finds extensive utilization within the Internet of Things (IoT) domain. While the advancements in 5G promise incredible speed and scale for IoT operations, they also introduce a new set of security challenges. The security models designed for 4G/LTE cellular networks won’t seamlessly cover the complexities of 5G IoT services. To tackle these concerns, it’s essential to adopt proactive designs that anticipate and mitigate potential threats. Building robust security features directly into the design of 5G networks is more effective than trying to address these issues as they emerge.