Sensors are an electronic device for interpreting analog or electrical stimuli in the outside world, including temperature, sound, motion, smell (including smoke), and pressure. These sensors are a key aspect of the Internet of Things, which relay information from these tiny devices to mostly digital communications networks.

Sensors come in a variety of forms, shape, sizes, and can vary by energy needs and efficiency. They can be built into electronic devices, stacked on top of them in 2.5D or 3D-IC configurations, or connected externally.