Ruth was a woman from Moab.  She married the son of a woman named Naomi, who had come to Moab from Bethlehem during a time of famine.  Both Naomi and Ruth were widowed, and together they returned to Bethlehem.  There Ruth was befriended by a man named Boaz.  Eventually they were married and had children.  Ruth was the great-grandmother of King David and an ancestor of Jesus.