A growing share of the appliances we test arrive with some version of the word intelligent printed on the box. Having now opened a lot of those boxes, we can offer a reasonably confident summary of what it usually means, and a short test for telling the useful cases from the decorative ones.
Most of the time it is a sensor and a rule
The common case is a device that reads one or two inputs and picks a response from a short list. A humidity reading changes a fan speed. A weight sensor changes a cook time. This is genuinely useful engineering, and it is also roughly what a thermostat has done since long before anyone put a robot on the packaging.
None of that is a scandal. The gap worth noticing is between what the word implies to a shopper and what the device actually does, because that gap is where money gets spent for nothing.
Sometimes it is real, and you can feel it
The cases where the claim earns its keep tend to share a property: the device behaves differently in month three than it did on day one, because it has adapted to your home rather than to an average home. A vacuum that has learned the actual shape of your floor. A device that has worked out when you are usually in.
That is a meaningfully different product from one that ships with a good default and never changes again.
The question to ask in the aisle
Does this thing get better at my house specifically, and can it be wrong in an interesting way?
The second half matters more than it sounds. Something that genuinely adapts can also adapt badly, and the honest products tend to admit that somewhere in the manual. A device that claims intelligence but has no described failure mode is usually a device with a lookup table and a marketing department.
Neither answer makes it a bad buy. A simple appliance that does one thing reliably is often the better purchase. But you should know which one you are paying for, and the box is not going to tell you.