A "biological mother" is a mother who owns the same blood as her child.
A "mother-in-law" is the name given to the spouse's mother.
A "stepmother" is the new wife of someone's father or mother.
A "surrogate mother" is an individual who consents to be impregnated with another's sperm in order to conceive a child for someone else/for a couple unable to have children naturally (such as an infertile couple or a same-sex couple: like a male/male or female/femalecouple).
