They both could be Southern.
Southern is an branch of Baptists..so is Freewill,Northern,Independent and there are more...
SBC stands for Southern Baptist Conference. Look in the phone book and you will be able to see who belongs to what.
They are all Baptist because they all believe the same, but they all belong to certain conference to distinguish them. Mainly from National Council of Churches.
Independent have more say so over who governs/teaches them..
Baptists' stand out Thur immersible baptism (no infants) and that if you have once accepted Christ as your Savior then you are always saved.
Not free to sin, like some think, but that we are accountable to God and being still in the flesh we do sin and ask forgiveness w/true repentance.