Section 133A of the Income-tax Act, 1961 empowers income tax authorities to conduct surveys to collect information useful for tax assessment. This section allows authorities to enter any business premises, verify books of account, and gather evidence without prior notice. The survey can be conducted during business hours and is aimed at discovering undisclosed income or verifying the accuracy of returns filed. It is significant as it helps in curbing tax evasion and ensuring compliance. The burden of proof lies with the taxpayer to explain discrepancies found during the survey. Practically, this section is crucial for maintaining the integrity of the tax system and ensuring that taxpayers adhere to their reporting obligations.