That is good news for you! It means your expenses (deductions) are higher than what IRS gives you as standard amount for expenses (called standard deduction).
For example, the IRS has standard deduction of $6300 for Single individuals. Your taxable income is lowered by that amount. But if your deductions are higher than $6300, then your taxable income is lowered by your amount, thus reducing your income even more, which results in bigger refund/smaller tax bill.
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