Here's why:

* Oxides are compounds formed by the reaction of oxygen with another element. While water contains oxygen, it also contains hydrogen. It's not simply oxygen reacting with another element.

* Hydrides are compounds formed by the reaction of hydrogen with another element. Again, while water contains hydrogen, it also contains oxygen. It's not simply hydrogen reacting with another element.

Water is a unique compound with its own specific properties and chemical structure. It's not accurately classified as either an oxide or a hydride.