In taste it is closer to garlic than leeks, not quite as pungent and strong as garlic, it has a milder softer somewhat sweeter taste. Unlike true Garlic it is edible raw and goes good in a salad.
The plant, in addition to producing the large edible garlic like clove also produces a smaller hard shelled bulb on the outer surface. These small bulbs are not commonly eaten, although they can be, they are more commonly used to propagate more Elephant Garlic plants.
Unlike true Garlic, Elephant garlic doesn't need to be divided periodically. It can be left in the ground without fear of rot and over winters nicely, it IS after all a perennial.