5. Sensors and Actuators

All IoT applications need to have one or more sensors to collect data from the environment. Sensors are essential components of smart objects. One of the most important aspects of the Internet of Things is context awareness, which is not possible without sensor technology. IoT sensors are mostly small in size, have low cost, and consume less power. They are constrained by factors such as battery capacity and ease of deployment. Schmidt and Van Laerhoven provide an overview of various types of sensors used for building smart applications.