A satellite dish is a curved, bowl-shaped antenna that receives signals from satellites orbiting Earth. You've probably seen these mounted on roofs or sides of houses: they look like large metal or plastic bowls, usually white or gray, pointed up at the sky.

Here's how they work: satellites orbiting thousands of miles above Earth broadcast television programs, internet data, or other information as radio waves. The dish's curved shape acts like a catcher's mitt for these signals, gathering them from a wide area and focusing them onto a small receiver at the center. That receiver then sends the signal into your house through a cable.

The dish must point in exactly the right direction to work, which is why installers spend time carefully aiming them. Even a few degrees off target can mean no signal. Satellite dishes became common in the 1980s and 1990s when people wanted more TV channels than regular antennas could provide. Early dishes were enormous, sometimes ten feet across, but modern ones are much smaller because technology improved.

Today, satellite dishes bring television and internet service to rural areas where cable companies haven't run wires. They're also used for weather forecasting, military communications, and scientific research. Some dishes receive signals, while others can also send them back up to space.