IoT devices usually consist of four main components as follows:   

• SENSORS: A sensor or device is an important component for gathering live data from the surrounding environment. The nature of this data can vary. This could be as simple as your phone having a temperature sensor, GPS, an accelerometer, or as complex as a live video feature on a social media platform. Sensors make it possible for IoT devices to CONNECT to the real world and environment.
• Connectivity: Upon collection, all data is sent to a cloud infrastructure. This could be done by connecting the sensors to the cloud using a variety of communication mediums such as mobile or satellite networks, Bluetooth, WI-FI, WAN, etc. Various IoT devices use different types of connectivity.
• Data Processing: Once the data has been collected, and has reached the cloud, it is the responsibility of the data processors to process it. Data processing software can enhance IoT devices in a wide range of ways, from adjusting the temperature of the air conditioner to recognizing faces on mobile phones.
• User Interface: An IoT device interacts with a user through a User Interface. A user interface is the visible, tangible component of an IoT system that can be accessed by users. It involves presenting the information in a way that is valuable to the end-user. A well-designed user interface will simplify the experience for users and ENCOURAGE them to interact more. Information needs to be made accessible to end-users in some way, like sending them ALERTS via notification, email or text message.