J-pop is music from Japan that is very popular among the people who live there. It is kind of like pop music in America, but in Japanese language. Just like how you know lots of singers and bands in America, there are lots of popular singers and bands in Japan who make J-pop music.
Some people might also think of J-pop as music that is more upbeat and exciting than other types of music from Japan. You might hear J-pop in lots of different places, like on TV, in stores, or even just when people are walking down the street.
Some J-pop singers and bands even have their own unique styles and dance moves that people can recognize right away. And just like how you might have your favorite singers or bands in America, there are lots of people in Japan who have their favorite J-pop musicians too.