A gNB (Next Generation NodeB) is the core radio access node in a 5G New Radio (NR) network, functioning as the evolution of the 4G LTE "eNB." It operates by using high-frequency radio waves and advanced signal processing to manage communication between user equipment, like 5G smartphones, and the mobile core network. A gNB is composed of several advanced technologies, the most notable being Massive MIMO (Multiple Input, Multiple Output) antenna arrays, which allow it to transmit and receive multiple data signals simultaneously by creating narrow, targeted "beams" toward individual users. This beamforming technology is essential for managing the high data volumes and speed requirements of 5G. The gNB also performs sophisticated resource scheduling, dynamically allocating frequency bandwidth based on real-time traffic demand. Furthermore, the gNB architecture is often split into a Centralized Unit (CU), which handles non-real-time functions like session management, and a Distributed Unit (DU), which handles real-time signal processing and interacts directly with the radio equipment. This functional split allows for greater flexibility and lower latency. By continuously communicating with the 5G Core, the gNB facilitates handovers as users move between cells and ensures that quality-of-service parameters are maintained, effectively providing the high-speed, reliable connectivity that defines the 5G user experience.