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.

One of the most important breakthroughs in modern communication lies in an overlooked place. It’s printed onto envelopes, just below the address. Although we think nothing of the ZIP Code these days, ...

In general, the 25 wealthiest ZIP codes in Silicon Valley have high median incomes and median home values, but they can differ a lot when you look at demographics. All of Silicon Valley's top 25 ...