Technological developments in micro-electro-mechanical systems and digital electronics motivate to development cheapest efficient tiny multi-functional sensor devices. A collection of sensor devices forms a network like Wireless Sensor Network (WSN) which is more and more essential in various wireless applications. The sensor devices are limited in power, bandwidth, communication range, and processing power. The WSN nodes are generally mobile in many applications, and the topology is dynamic owing to the constrained node energy. The WSN has many potential applications that are smart homes, military surveillance, healthcare, agriculture, and vehicular networks. The WSN necessitates efficient routing, data aggregation, mobility models, and clustering methods to satisfy the application-specific requirements. In recent years, the integration of WSN with other networks is a significant topic in which the advantages of WSN are employed to develop other network functionalities like VANET safety.