The Philippine eagle has a sharp hooked beak for shredding prey. They eat large amounts of food in a short period of time, which will be stored in the crop (this helps with slower digestion). Essentially, it's an expansion of the esophagus where food can be stored and slowly released down into the ventriculus (gizzard/stomach) along with pepsinogen and hydrochloric acid that is secreted from the proventiculus. There whatever they consumed is taken through the intestines and excreted. Food they can not excrete (hair, feathers and bones occasionally) is compacted in the ventriculus and "coughed" back up. We typically know of these as "pellets". Owls are another great example of a bird that regurgitates pellets. 

Contrary to popular belief, birds bones are not hollow to make them lighter for flight. They need so much oxygen that it actually extends into their bones. Hollow bones would break very easily, or so you'd think. Birds actually have a skeletal system that is much denser, resulting in strength and stiffness. As a chick grows, the air sacs in the lungs actually spread to bones creatings the hollows that will be there the rest of their lives.