Help understanding the meaning of certain fantasy concepts

The textbook "A Glossary of Literary Terms" includes this passage regarding the definition of Chivalric romance:

Chivalric Romance is a type of narrative that developed in twelfth-century France, spread to the literatures of other countries, and displaced the earlier epic and heroic forms. Romances were at first written in verse, but later in prose as well. The romance is distinguished from the epic in that it does not represent a heroic age of tribal wars, but a courtly and chivalric age, often one of highly developed manners and civility. Its standard plot is that of a quest undertaken by a single knight in order to gain a lady's favor; frequently its central interest is courtly love, together with tournaments fought and dragons and monsters slain for the damsel's sake; it stresses the chivalric ideals of courage, loyalty, honour, mercifulness to an opponent, and elabourate manners; and it delights in wonders and marvels. Supernatural events in the epic had their causes in the will and actions of the gods; romance shifts the supernatural to this world, and makes much of the mysterious effect of magic, spells and enchantments.

I am wondering what the bold parts mean.