Most all new toilets are a water saver style toilets, and are designed to deliver two types of flushes. First is the quick flush for urine, and that means you push down then quickly release the handle. Less water is used so there is a water savings over emptying the tank. Second flush type is for solids, and you simply hold down on the handle until the flush is complete. All the water in the tank is used, but the newer tanks are smaller, so less water is used compared to the toilets of the 50's and 60's. It's all about water savings.