Apple recently introduced its first foldable phone, called iPhone Duo. A foldable phone can bend in the middle. When it is closed, it works like a small phone. It can fit easily in a pocket. When users open it, they get a much larger screen. This screen can help with videos, games, reading, and work. (apple.com)

The phone uses a hinge. A hinge is the moving part between both parts. It helps the phone open and close smoothly. The outside screen works while the phone is closed. The inside screen is ready after opening. Users can also put different apps side by side. (apple.com)

Imagine you are riding a train. First, you check a short message outside. Then, you open the phone for a travel video. You can also view a map beside your notes. The device changes from small to large in seconds.

This design offers different choices in the same device. Use the small screen for quick tasks. Use the large screen when you need more space. Some people may still prefer a normal phone. Still, the idea is clear: carry less, but see more.