IoT device
A physical product with a sensor or actuator, a small computer and a way to connect, built to send data or receive commands.
A typical device combines a sensor (what it measures), a microcontroller (its small brain), a radio module (how it connects), a power source and an enclosure. Some also act on the world, for example by opening a valve.
Why it matters for business
The device decides much of the total cost: hardware price, battery life, installation effort and how long it can stay in the field without a visit.