Equity has a variety of meanings in the financial world.
1. In stocks it refers to the ownership interest in a corporation in the form of either common or preferred stock.
2. Shareholders equity is a term used to describe the difference between total assets minus total liabilities.
3. In real estate, equity is the difference between what a property is worth and what the owner owes against that property (i.e. the difference between the property's value and the remaining mortgage or loan payments on that property).
4. In the context of a trading account, equity equal to any cash value plus the the market liquidation value of the securities in the account.