The Internet of Things is a paradigm where everyday objects can be equipped with identifying, sensing, networking and processing capabilities that will allow them to communicate with one another and with other devices and services over the Internet to accomplish some objective. Internet, the networks of networks avails us the world at one click. This paper is a survey on Internet of Things which is believed to be the next evolution of Internet. The Internet of Things (IoT) bridges the cyber and the physical worlds. Ultimately, IoT devices will be ubiquitous, context-aware and will enable ambient intelligence. This article reports on the current state of research on the Internet of Things by examining the literature, identifying current trends, describing challenges that threaten IoT diffusion, presenting open research questions and future directions and compiling a comprehensive reference list to assist researchers. Then, there is an example of IoT in a smart city.