We call it an eye, but it's not really an eye. A glaring error doesn't really glare, and the tongue of a shoe isn't really a tongue, it only reminds us of a tongue. These are metaphors, names for things that aren't actually what the things are.
Dreams are often metaphors, too.
A Parable is also a metaphor. Using an imaginary story to illustrate deeper moral concepts, the parable teller imparts wisdom in ways that are easier to remember. The Genesis story, for example, is a parable describing the infinitely complex process of evolution. Our language consists entirely of metaphors, just try to find a word that doesn't describe something. The word 'Consciousness', for example, is a metaphor for something we try to describe, but it still doesn't quite explain it.