BTU, or British thermal unit, is the industry-standard used to measure the heating efficiency of furnaces. In addition to BTU ratings, furnace manufacturers might include a Manual J Load rating and a percentage of energy efficiency.
A bond is a debt investment in which an investor loans money to an entity (typically corporate or governmental) which borrows the funds for a defined period of time at a variable or fixed interest rate. Bonds are used by companies, municipalities, states and sovereign governments to raise money and finance a variety of projects and activities.
The primary difference between debt and equity financing is that debt must be repaid at maturity, while there is no obligation to repay equity financing. Interest must be paid on debt while the company is under no obligation to issue dividends on equity financing. The interest paid is tax deductible while dividends are not. Finally, debt holders do not have the right to vote on company matters as equity holders do.