Form 16 is a certificate issued by your employer that contains the TDS which is deducted from your salary and deposited with the authorities. It also includes the other income sources of the employee and is issued every quarter. It contains all the information you need to prepare and file your income tax return. If you are a salaried individual and want to know how to save tax on salary or how to claim an income tax refund, just check your Form 16 and know all the deductions and benefits availed by you from your employer.