So it's a snow spade? Not sure I agree with this definition.
I do not agree with the definition, and would point out, among other things, that the internet is notorious for proliferating things and inundating us with sheer quantity whether they are right or wrong.
Getting my definitions from the custom of use and peripherally from older editions of Merriam Webster, and with the cautionary note that I am an American, and thus my usage is too, I would define a spade as a subspecies of shovel, distinguished by being designed to be pushed into the earth with the help of a foot. It is defined by its function rather than by its shape.
Traditionally, but not necessarily, It will have a sharp flat end, a blade longer than it is wide, and a short handle, but above all it must be designed to be pushed into the earth with a foot. A snow shovel and a grain shovel and a coal shovel and a fireplace shovel, all with flat ends, are not spades, but a round ended one which you push into the ground with your foot in order to dig holes, is more a spade than not. A long handled shovel with a spade-like blade is generally called a shovel, the long handle making its use more general, for clearing, throwing and moving material as well as for making holes.
In keeping with the spirit of this thread, however, and not wishing to drift off subject, I will mention that I have been hoarding spades because I have heard a rumor that the Obama administration plans to outlaw all tools with sharp edges.