Most urinals fall into three broad categories:
Full-length urinals extend from below chest high all the way down to the floor and beyond. The drain is under floor level. You don't see many of these anymore, since installation involves altering the floor. In my opinion, the best kind. One size fits all, and you can stand as near or as far from the urinal as you want, without making a mess. Easy to clean, as there is little collateral damage. Also makes it easy to mop the floors, as you can mop into the urinals.
These are the predominant urinals found today. These are the ones that go from below chest height to about thigh length. Because of this, there is always one in kiddy-height (short urinal), reducing overall urinal capacity of the restroom. This is significant in smaller restrooms, where two useful urinals becomes one useful urinal, and the one everyone avoids. These urinals are cheaper to manufacture, and easier to install.
These abominations are urinals that pretend at being toilet bowls. They are similar in height to half-length urinals, but the shape is similar to that of a toilet bowl. It sticks out about two feet from the wall. The shape is totally stupid, as you can't really sit on it and take a crap. It may be some weak attempt at reducing collateral damage, but it hinders correct urinal usage, since standing too close results in contact between the urinal and the thighs - a definite no-no. These should all be replaced by regular half-length urinals.
Don't even get me started on trough-style urinals, and urinals without privacy dividers....