The automotive business has changed as a result of connected vehicles, which have improved urban adaptability and livability. The influence of Vehicle Ad-hoc Networks (VANETs) and their development into Intelligent Transportation Systems (ITS) is examined in this paper. The Internet of Vehicles (IoV), which facilitates vehicle-to-vehicle (V2V) communication, is built on top of VANET. Even though VANETs have advantages like increased entertainment and road safety, managing a variety of services with different Quality of Service (QoS) needs can be difficult. Software-Defined Networking (SDN), which facilitates effective control of mobile nodes, inter-operations, and resource allocation, is essential in addressing these issues. The paper is reviewed that how VANET technologies have developed over time, showing how they are now used for more than just safety services. Examples of these uses include IoT-based advertising, surveillance, and vehicle cloud computing. However, the inherent difficulties of VANETs, including changing node densities and high mobility, need programmable networking designs like SDN .Splitting architecture of network to control plane with data planes. Strategically, and SDN-enabled Vehicular Networks (SDVN) offer a centralized view for efficient management.