26AS is a consolidated statement showing the tax credit associated with our PAN. It shows how much tax has been received by the government by way of TDS deposited by the deductor (employer, bank) on our behalf, Advance tax deposited by us, self-assessment tax deposited, etc. It is important to match tax payments and TDS deducted with 26AS before filing your income tax return to get a tax credit as we can take a tax credit of only those items appearing in our 26AS.