Equity can also denote
ownership. When you buy a house, you are said to gain equity. Equity is basically considered an
asset, and the value of your home (or any other major asset you own, like a car), less any debt outstanding on it (a
mortgage, usually, or maybe other financing for a car or boat) is the amount of equity you have. This is mostly important when talking to a bank or applying for credit - they'll consider not only the amount of money you have saved up, but also any equity you have in your home or other assets as being part of your net worth. That's why you might hear the term homeowner's loan, or home equity loan - those are loans secured by someone's equity in their home.
The stock markets are often called the equity markets, and stocks are also called equities, because stock in a company is part-ownership.