Why is this variable equal to a function?

I dont understand why , song = repeat_stuff(lyrics)
can anyone help? thx

So song is a variable we can call later, repeat_stuff() is the function written at the beginning of the lesson, and will repeat the argument given. (remember that it will repeat 10 times by default although that can be changed with the second argument) so we feed lyrics into repeat_stuff() without a second argument so now song is set as lyrics repeated 10 times.