VANETS are considered as one of the most prominent technologies for improving the efficiency and safety of modern transportation systems. A VANET will be a major contribution toward the realization of Intelligent Transportation Systems. The main aim of VANET ranges from improved road safety, time critical safety applications, optimized traffic flow, delay tolerant, and infotainment and so on. High relative nodes pace and high active nodes mass has offered a typical challenges for connectivity within VANET. A lot of researches from the industry, academia, and standardized agencies to develop standards and prototypes for vehicular networks. In this paper, a complete survey on existing technologies in VANET is being presented. KeywordsVANET (Vehicular Adhoc NETwork), OBU (On Board Unit), RSU (Road Side Unit), AU (Application Unit), DSRC (Dedicated Short Range Communication), WAVE (Wireless Access for Vehicular Environment). INTRODUCTIONVehicles are needed for transportation. People drive cars so that they can have the freedom they need to be able to get where they need to go when they need to get there. Due this reason number of vehicles is increased. The increase in vehicles leads to lot of mishaps on the road which can happen in highway or city areas. To overcome these catastrophes a good communication network need to be built between the vehicles. This leads to a new advance technology Vehicular Adhoc NETwork (VANET). VANET is one of the sub branches of MANET technology. In Mobile Adhoc NETwork (MANET) each mobile is considered as node whereas in VANET each vehicle is considered as a node. These days, an immense number of auto organizations are conveying vehicles with in-auto sensors, installed figuring and remote specialized gadgets, and navigation systems (e.g., GPS) in preparation for the use of large-scale vehicular networks. By using different sensors, cameras and communication competence, vehicles can gather and interpret information with the intention of helping the driver to make a judgment, particularly in driver support systems. Fig 1 gives the comparison between MANET and VANET. The nodes in MANET and VANET are self-composed, selfguided specially ad hoc network and decentralized in a distributed manner with a self observed authority or a server to direct the communication. Nodes themselves go about as servers and/or clients by exchanging and sharing data like peers. Even though VANET is a subpart of MANET, there are lot of difference in the characteristics of MANET and VANET. The MANET can contain many nodes that have uncontrolled moving prototypes. But since VANET is created generally by vehicles so node movement is limited by factors like road lane, traffic and traffic regulations. MANET vs VANET MANET Characteristics and Applications MANET CharacteristicsDistributed operation: For the central control of the network operations, thusly there is no backgrounds arrange rather the control of the network is conveyed among the nodes. The nodes included in a MANET ought to coordinate with one anoth...