For example, the saddlebill bird has a very long, sharp beak which is red, yellow and black. It stabs water animals, so this type of beak is required.
Eagles and other birds of prey tear flesh using both their beak and their talons or claws and so they have very sharp beaks. Waxwings on the other hand eat berries, so their beaks are more adapted to clasping tiny berries.
A bird has no teeth, so its beak is very important to assist with feeding. However, a lot of the 'chewing' is actually done within the second part of the bird's stomach, which is commonly known as the 'gizzard'. Some birds actually swallow small pebbles or grit to assist the gizzard in breaking down the food.