Ruth, is an interesting book.
Naomi and her husband travel because of famine, taking their two sons with them to Moab. The sons marry, one to Ruth one to Orpah. Naomi's husband, and their two sons die, of undisclosed circumstances. Naomi tells her daughters in law to stay in Moab, with their families and friends. Ruth cannot leave her to be alone. She insists on going with her, to care for her in her old age. She becomes a gleaner. A gleaner is a person, that while the harvest is happening, comes along behind, and can pick up the grain that the main harvesters miss. Boaz, is impressed with her style, and work ethic. He asks his servant who she is, and why she is gleaning. Gleaning was for the poor. Then he directs his servant to make sure that there is grain for her to glean. He asks her to partake of the food that he has prepared. And she returns to Naomi with food for them both. Boaz is smitten, and although it is not okay, he decrees and marries Ruth. Although the marriage is short lived, as he dies shortly thereafter.
I have always seen it as a story of doing the best you can at whatever you do. Of taking care of the poor, and the elderly.
Also, in Ruth, there is the saying "Thy people will be my people, thy God, my God" said by Ruth to Naomi, when convincing her that she would follow her to Bethlehem.
To me it is a book about Charity.