The word parable comes from the Greek para (beside or alongside) and ballein (to throw). Thus the story is thrown alongside the truth to illustrate the truth. Hearers and readers, by sensing the comparison or analogy between the story and their own situation, are prodded to think. In intepreting parables we need to ask, What is the point of the story? What spiritual truth is being illustrated? What analogy is being made?1
1 Roy B. Zuck, Basic Bible Interpretation (Colorado Springs, CO: Cook Communications, 1991), 194.