Why is this the answer?

The answer is windmill because this clever riddle uses fun word pictures to describe an amazing machine. A windmill is a tall, strong building that helps people by catching the wind. Let us look at the first part of the riddle: "I have four wings but cannot fly." When you look at a windmill, it has huge wooden or metal blades, called sails, that stick out from the center. These blades look a lot like giant wings, like the ones on a bird or an airplane. Even though they look like wings, the windmill itself is fixed right to the ground and cannot fly up into the sky. Its purpose is to stand still so its big 'wings' can catch the air and spin when the wind blows to make power. The next clues are "I never laugh and never cry" and "On the same spot always found." A windmill is a machine built out of wood or stone, not a person or a pet. It does not have feelings, so it cannot be happy and laugh or be sad and cry. It is also built in one place, usually a spot where the wind is strong. It stays there forever, always "on the same spot," never moving or running away to explore. Finally, the riddle says the machine is "toiling away with little sound." "Toiling away" means working very hard. Windmills work hard all the time, using the wind's energy to turn machinery inside the building. In the past, people used this power for big jobs like grinding up grain into flour for baking bread or pumping water out of the earth for farmers. When you stand close to a windmill, you might hear a low, steady whirring sound as the big blades turn and the gears move, but they do not shout or make a big, loud fuss. They just keep working quietly and steadily, using the invisible wind to help people get important jobs done. That is why the windmill is the perfect answer for all the parts of this smart riddle.