Are the breasts hard inside?

From the very beginning of my breasts, I felt something hard on both sides, like big balls. I thought it was normal, because they seemed to be tied together in knots and it was probably something anatomical. And today I feel them. But the other day I touched my friend's breasts, hers were a little bigger than mine, and they were also softer, I almost didn't feel anything hard. Now I don't know if this is normal for me. My breasts are firm, but not soft like others'.