You never need to water a concrete yard, and there is no upkeep like there is with grass. The disadvantage is it's less visually appealing, and very rough.
The advantage is it's easy to maintain. You don't need to mow or fertilize it. The disadvantage is it's not as attractive and if you have kids it's not really a great surface for them to play on.
A concrete yard makes certain sports possible and you never have to mow it. Grass is prettier than concrete and it also doesn't hurt as much to fall on grass.
