The Internet of things ( IoT ) is a new revolution of the Internet. It makes objects themselves recognizable, obtain intelligence, communicate information about themselves and they can access information that has been aggregated by other things.The Internet of Things is a paradigm that involves physical objects with capabilities of sensing, information processing and communication through wireless or wired connection. These physical objects having embedded intelligence and hence decision-making capabilities act as smart things. The paradigm of IoT embraces various domains including sensors, information and communication technology, memory space, data analytics, machine learning and security and privacy mechanisms.IoT refers to a type of network to connect anything with the Internet based on stipulated protocols through information sensing equipment to conduct information exchange and communications in order to achieve smart recognitions, positioning, tracing, monitoring, and administration. The ‘things’ are constrained in terms of computing power, memory space and data rate and hence need innovative approaches to address the technical challenges present in the real-life implementation of the concept. The IoT allows people and things to be connected 4As ( i.e. Anytime, Anyplace, with Anything and Anyone ).IoT systems have applications across industries through their unique flexibility and ability to be suitable in any environment. They enhance data collection, automation, operations, and much more through smart devices and powerful enabling technology.The aim of this paper is to provide a briefly discussion about what IoT is, how IoT enables different technologies, about its architecture, characteristics & applications, IoT functional view and highlights of the technical challenges therein open for research community.