VANET uses vehicles as mobile nodes which are a subclass of mobile ad hoc networks (MANETs) to provide communications among nearby vehicles and between vehicles and nearby roadside equipment but apparently differ from other networks by their own characteristics. In VANET the vehicles can communicate with each other in a range of 100-300m using multi-hop communication. Safety is major concern of VANET because vehicles in VANET form a self organizing network. VANET provide drivers information and warning about nearby area traffic, road conditions, environment hazards and information related to other vehicles in the network.

VANETs support a wide range of applications from simple one hop information dissemination of, e.g., cooperative awareness messages (CAMs) to multi-hop dissemination of messages over vast distances.

Applications of VANETs are:

• Electronic brake lights: It allow a driver (or an autonomous car or truck) to react to vehicles braking even though they might be obscured.
• Platooning: It allows vehicles to closely (down to a few inches) follow a leading vehicle by wirelessly receiving acceleration and steering information, thus forming electronically coupled "road trains".
• Traffic information system: It use VANET communication to provide up-to-the minute obstacle reports to a vehicle's satellite navigation system
• Road Transportation Emergency Services: Here VANET communications, VANET networks, and road safety warning and status information dissemination are used to reduce delays and speed up emergency rescue operations to save the lives of those injured.
• On-The-Road Services: It is envisioned that the future transportation highway would be "information-driven" or "wirelessly-enabled". VANETs can help advertise services (shops, gas stations, restaurants, etc.) to the driver, and even send notifications of any sale going on at that moment.

Fig: VANET Architecture: