IOT can be defined in various ways. It involves many features of life such as connected homes, roads, devices and cities which can trace an individual’s behaviour. It is expected that around 1 trillion Internet-connected devices will be accessible with mobile phones as the only one means of the applications connecting all of associated things. It is the IoT only which made billion objects to interact and communicate all over public and private worldwide networks. Around 12.5 billion things were connected in 2010-2011. The IoT approach has attracted many researchers due to its huge future-predicted impact on the daily life of people and society. Remote communication with the help of new mobile applications is made possible with the help of tiny nodes known as sensors. Therefore, WSNs have become the crucial subpart of the IoT platform. When things are connected in a network, they work together as the one scenario and provide service as a whole and not as a collection of independently working devices. This is useful for various real-world applications and services. For example, this approach would be useful for smart homes, smart transportation, smart healthcare, etc. IoT is useful for the needy and disabled people because it serves and supports many human activities at a huge scale. Machine learning techniques, block chain services, cloud services, security paradigms, named data networking, software-defined networks have boost up the IoT technology at a large platform and have made it more sustainable. WSNs are well suitable for long-standing environmental data retrieval for IoT illustration.