EMI stands for Equated Monthly Installment, which is a fixed payment amount made each month to repay a loan over time. It is used to pay off both the principal and interest portions of the loan each period so that the loan is fully retired at the end of the repayment term. The document provides an example calculation of an EMI for a loan and explains that EMI makes budgeting easier for borrowers by keeping the monthly payment amount consistent. It also describes how to calculate EMI using the PMT formula in Excel.