Metaphor and metonymy are each distinct processes. Where metaphor describes one thing in terms of another, metonymy allows one thing to stand in for another. Metonmy also facilitates understanding, while allowing us to focus on specific aspects of what's being referred to.
Related
- metaphors-structure-our-interpretation-of-the-world
- metaphors-create-coherent-systems-of-meaning
- structural-metaphors-reveal-and-conceal-different-aspects-of-experience
- orientational-metaphors-organize-concepts-relationally
Reference
Lakoff, George, and Mark Johnson. Metaphors We Live By. University of Chicago Press, 2008.