Enterprise Value represents Market Capitalization minus Cash and Equivalents plus Total Debt, Minority Interest and Preferred Stock.
This value is translated into Financial Statements Currency, rather than being in Price Currency.
If EV < Market Cap, the company has net cash. If EV > Market Cap, the company has net debt. If EV < 0, there is more cash in the company than the value of the Mkt Cap and Debt combined! This signal is often appreciated by deep value investors.
Because EV is a capital structure-neutral metric, it is useful when comparing companies with diverse capital structures. In contrast, the PE Ratio will be significantly more volatile in companies that are highly leveraged.