Form 26AS is a statement of all the taxes you have already paid. It gives an overall view of all the TDS deducted from your income in the financial year at various sources. These could be tax deducted on salary, commission income, interest received from Fixed deposits, etc. It also shows the details of the deductor of TDS, i.e. your employer, bank, or your tenant. Apart from TDS, Form 26AS also shows any advance tax or self-assessment tax that you may have paid during that financial year.