ELI5: Explain Like I'm 5

1seg

1seg stands for “One-segment Digital Television Broadcasting” and is a type of digital television broadcasting in Japan. 1seg broadcasts are composed of data that comes in small “segments” and can be watched on small devices like smartphones and tablets. The 1seg signal is sent over the same frequencies that FM radio uses, so if you have a 1seg compatible device, you can watch 1seg broadcasters without the need for an antenna or satellite dish. You can watch all kinds of TV programs, including news, sports, music, and entertainment.