@roxytalks, claire: Agreed about a powered parachute; that could correctly be called an aircraft, as could a hang glider. But a normal parachute is not an aircraft. It is a device designed to control or cushion a fall through the air. It does not in and of itself "fly".
The term "aircraft" applies to any device used for transport through the medium of air. However, as a general term, it is most often incorrectly used to describe such as a passenger 'plane'. The correct term is, in fact, aeroplane, aero being from ancient Greek 'ero' or air, and plane, also from ancient Greek derived from 'wandering,' hence, 'travelling on air'. This requires a particular shape to the 'wing' or 'aerofoil' also referred to in American English as 'airfoil', which, if you think about is actually a misnomer as the device is not intended to 'foil the air' but to use the air as a lifting device.
The design of an aerofoil is such that where the air meets the leading edge and is split, the air flowing over the top has to travel further than the air which flows underneath. This creates 'lift' because the air travelling over the top is therefore thinner (being the same quantity as that travelling under) because it has to travel further to reach the same destination at the rear of the aerofoil section. Power in one form or another is required to force the aerofoil through the air, but the lift is created by the shape, not the power. Thus a jet airliner is an aircraft or aeroplane, but a balloon is only an aircraft.
And roxy, it is not silly to have read the article and revised your notion. That is how we all learn. Silly would be to maintain a fixed notion regardless of the information around you. That's the sort of thing idiots do.