差额 (chā é) refers to a difference or discrepancy in amounts, especially financial figures, quotas, or vote counts — it is a numerical shortfall or surplus. The general word for 'difference' is 差别 (chā bié); 差距 (chā jù) emphasizes a gap or disparity; 出入 (chū rù) is a discrepancy between two statements; and 差异 (chā yì) is a more abstract difference. 差额 is the term to use when talking about real numbers or balances, such as a budget shortfall.