Sensor network is a subset of Internet of Things, where the connected devices are sensors. The purpose of such deployment is usually to collect information for a specific application : agriculture, home automation, energy management, smart city, natural disaster prevention... Since sensors are connected devices with a uniform and identified functionality (converting a physical information into a numerical one), the early work one semantics for connected devices focused on sensors.

The Internet of Things contains, along with sensors, connected devices in charge of computing, and actuation (the opposite of sensing : converting a numerical information into a physical one, e.g. what does a servomotor).