Moving into the future world, life will be getting more easier and easier because of internet of things (IOT). Nowadays with increased need for surveillance, monitoring and data collection IOT has become more important. Today almost all devices are equipped with sensors and are controlled by controllers such as from cars to vacuum cleaners, rockets to Vernier calipers, air conditioners to water pumps. By embedding intelligence in everyday objects, they turned into smart devices and can be controlled from anywhere in the world. This paper discusses about internet of things and its advantages and disadvantages. It discusses the applications of IOT in various fields such as city, agriculture, remote monitoring, smart street light, etc. This paper also tells about the history of IOT.