The advent of internet of things (IoT) has influenced and revolutionized the information systems and computing technologies. A computing conceptwhere physical objects used in daily life, will identify themselves by getting connected to the internet is called IoT. Physical objects embedded withelectronic, software, radio-frequency identification, sensors, actuators and smart objects converge with the internet to accumulate and share datain IoT. IoT is expected to bring in drastic changes and solutions to most of the daily problems in the real world. This paper explains in detail the keyconcepts of IoT, the applications of IoT, the challenges in establishing IoT. This work also explains in detail the future scope of IoT in different fields.