Vehicular Ad hoc Networks, also known as VANETs, are temporary wireless networks consisting of different types of automobiles as network nodes and the connections among these vehicles as links. VANET is a booming technology that has become quite popular in research, academia, and industry domains. A VANET can be considered as a moving network in which the nodes are automobiles. As VANETs are basically ad hoc networks, they have all the fundamental characteristics of ad hoc networks including computational and storage constraints. A network of VANETs can also be formed to enhance the safety and other services for vehicle drivers. VANETs are proven to be efficient in many real-life scenarios including traffic control and driver assistance. Information communicated through VANETs can definitely help to improve the user driving experience and avoid collisions. This paper discusses various deployment scenarios for VANETs along with the communication requirements and security concerns.