A hit song is a really popular song that lots of people like to listen and dance to. It's like when your favorite snack is pizza and all your friends love it too! A hit song is like that, but for music. When a song becomes a hit, it gets played on the radio, TV, and online, and people want to hear it on repeat all the time. A hit song can also make the singer or band famous and make them lots of money. So when you hear a song that you really like and you think it's very popular, that might be a hit song!