1 Chronicles 2:46

And Ephah, Caleb's (m) concubine, bare Haran, and Moza, and Gazez: and Haran begat Gazez.

(m) The difference between the wife and the concubine was that the wife was taken with a ceremony of marriage and her children inherited, while the concubine had no marriage ceremony, neither did her children inherit, but had a portion of goods or money given to them.