When we talk about "urban areas," we mean places where lots of people live close together, like big cities. Some urban areas in the United States have more money than others.
"Money" means having a lot of dollars or coins which people can use to buy things they want or need.
The people who live in the highest-income urban areas earn a lot of money from their jobs or businesses.
This means they can buy nicer houses, cars and clothes, and can afford to go on fun vacations or eat at fancy restaurants.
However, it is important to remember that not everyone in these areas is rich or has a lot of money. There are still many regular people who work hard and live modestly in these urban areas.