You might have seen images of old TVs with a series of colorful bars, called a test pattern. What were these for, and are ...

Most modern TV screens have a 16:9 (or 1.78:1) aspect ratio. However, movies made for theaters are shot in even wider formats, like 2.35:1. Since that's wider than your TV screen, you see those ...

In short, the black bars appear because the video's aspect ratio doesn't match your TV's. While companies like LG have released 21:9 TVs in the past, they have never really caught on.