A loan generally consists of two components; principal (the amount borrowed/loaned) and interest.
Giving or receiving a loan is not typically a taxable event, but the interest paid on the loan balance is typically taxable for the lender and, depending upon the purpose and nature of the loan, the interest may be deductible for income tax purposes by the borrower.
If you want a more detailed answer, you should post additional, and more specific, facts.