Anything that has a sensor attached to it and can transmit data from one object to another or to people with the help of internet is known as Internet of Things (IoT).
IoT devices include wireless sensors, software, actuators, and computer devices. They are attached to a particular object that operates through the internet, enabling the transfer of data among objects or people automatically without human intervention.
For example, IoT systems in your car identifies the traffic ahead and automatically sends out messages to the person you are about to meet of your impending delay. Even a pacemakers can be an IoT device that seamlessly communicates with other machines for a greater ease of life and convenience.
Connected devices are part of a scenario in which every device talks to other related devices in an environment to automate home and industry tasks, and to communicate usable sensor data to users, businesses and other interested parties. IoT devices are meant to work in concert for people at home, in industry or in the enterprise. As such, the devices can be categorized into three main groups: consumer, enterprise and industrial.