What does mon and ma mean in French?

They both mean "my". Mon is followed by a masculine gender noun, ma is followed by a feminine gender noun.

Ex: J'aime mon fils, ma mère et ma femme. (I love my son, my mother and my wife) - j'aime mon mari, ma soeur et ma tante (I love my husband, my sister and my aunt).

For both froms, the plural is "mes".