In the simplest sense, a smart object is any physical object that includes a
unique identifier that can track information about the object. More complex
smart objects may contain sensors and computers in addition to a unique
identifier, but the sensor and the computer may also be separate tools that
interact with a tagged object that has no electronic components. Radio-frequency
identification (RFID) tags and quick response (QR) codes can be attached to
everyday things to turn them into smart objects, as can other means of
identification like those that make smartcards work. More sophisticated smart
objects may look like blocks but contain computers and the ability to sense
position, proximity to other smart objects, light, heat, color, and so on.