Internet of things (IoT) is one of the fields, where much research work is being done. Nowadays, wireless systems which are based on IoT are developing very fast in different sectors. The Internet of Things is the kind of network in which any machine or tools can be operated without any interference of human beings The information shared among different objects will be more useful if a wireless sensor network (WSN) is used with the Internet of things. IoT is a combination of sensors and software with embedded electronics. The WSN based IoT system collects data from the environment through sensor nodes and data can be uploaded on the cloud. Users can access data from anywhere. In this paper, we discuss WSN based IoT systems, elements of the internet of things and the challenges of WSN based IoT systems. WSN nodes are generally small in size and are also battery-driven small machines. The energy- efficient data transfer technique can help in increasing the lifespan of the network.

Keywords : Internet of Things, WSN, sensor node, cloud computing.