What Causes Raised Skin Scar?

My question is, I have some elevated skin(don't know what else to call it), it is right above a section of my c section scar, I was 27 when I had my son now 33. Prior to that, when I was 17 I had my right fallopian tube taken out, they think it was because of a tubal pregnacy. They used the same "scar" for my c section. The area where the skin is elevated is on the right side, I am just wondering if that is normal.