In general, leverage refers to accomplish certain things which are otherwise not possible
i.e. lifting of heavy objects with the help of lever. This concept of leverage is valid in business also.
In finance, the term ‘leverage’ is used to describe the firm’s ability to use fixed cost asset or funds to increase the return to its owners; i.e. equity share holders. In other words, the fixed cost funds i.e. debentures & preference share capital act as the fulcrum, which assist the lever i.e. the firm to lift i.e. to increase the earnings of its owner i.e. the equity shareholders.
Leverage is also the influence which an independent variable has over a dependent/related variable i.e. rainfall over production. In financial context, sales& fixed cost over profit.