Most Americans know their ZIP code by heart. They type it into online forms, scribble it on envelopes and memorize it as part of their address. But not everyone knows the original meaning of the term.

We all have one, we know it by heart, and we share it with our neighbors. But chances are you haven't thought that much about this ubiquitous part of American life — the ZIP code. We all know about ...

Hanna Horvath is a CERTIFIED FINANCIAL PLANNER™ and Red Venture's senior editor of content partnerships. Fox Money is a personal finance hub featuring content generated by Credible Operations, Inc.