Ans 1 :Efficiency is the (often measurable) ability to avoid wasting materials, energy, efforts, money, and time in doing something or in producing a desired result. In a more general sense, it is the ability to do things well, successfully, and without waste. "Efficiency is thus not a goal in itself. It is not something we want for its own sake, but rather because it helps us attain more of the things we value". In more mathematical or scientific terms, signifies the level of performance that uses the least amount of inputs to achieve the highest amount of output. It often specifically comprises the capability of a specific application of effort to produce a specific outcome with a minimum amount or quantity of waste, expense, or unnecessary effort. Efficiency refers to very different inputs and outputs in different fields and industries.
Ans 2 : 

Equity is the amount of capital invested or owned by the owner of a company. The equity is evaluated by the difference between liabilities and assets recorded on the balance sheet of a company. The worthiness of equity is based on the present share price or a value regulated by the valuation professionals or investors. This account is also known as owners or stockholders or shareholders equity.