Meaning of unconnected device
Dumb devices (think sensors and actuators) were pretty easily defined as something that just did a simple task like reading temperature or sensing vibration and then, every now and then, reporting that information back to some kind of control system.
Meaning of connected device
Smart devices could perhaps save some data, run some computations on it, and create an alert based on some threshold or other that was reached.
Ecosystem of connected devices
In fact, as time goes on, the whole idea of an internet of individual “things” really won’t have much meaning. It’s a continuum, with low-capability, minimally-connected devices on one end and highly-capable, multilaterally-connected devices on the other.
Meaning of connected device
Ultimately, what makes a device “smart” isn’t the onboard compute and storage capabilities of the device itself but what it can do when it is connected to other devices and then to processing platforms that can act on that information.
Connectivity and platforms to do something useful
That’s why trying to pigeonhole IoT as smart or dumb today kind of misses the point. It’s the connectivity and the platforms that tie all these devices together that give the future of IoT its power.