What it is:
Wall Street is the name used to describe the place in New York City where much of the United States' financial industry is concentrated. The name "Wall Street" is also used frequently used to describe the financial services industry, generally.
How it works (Example):
Located near the southern tip of Manhattan, Wall Street is the heart of the American finance sector. It is home to the country's two major stock exchanges, the New York Stock Exchange (NYSE) and the American Stock Exchange (AMEX). It is also home to the headquarters of numerous brokerage houses and financial institutions.
Wall Street's central role as a hub of activity affecting the American economy has led its very name -- often shortened to "the Street" -- to be synonymous with high finance, all manner of investing and general economic prosperity.