Vehicle-to-everything communication is a comprehensive research field and technological paradigm concerned with enabling bidirectional information exchange between vehicles and a wide array of surrounding entities, including other vehicles (V2V), infrastructure (V2I), pedestrians (V2P), the network (V2N), and cloud services (V2C). As an academic concept, it investigates the communication protocols, network architectures, security, privacy, data management, and regulatory aspects necessary for establishing reliable, low-latency, secure, and interoperable connectivity across diverse communication links. Its significance lies in its potential to fundamentally transform transportation systems by enhancing safety through collision avoidance, optimizing traffic flow, improving energy efficiency, and enabling advanced functionalities for connected and automated vehicles.