IRS itemized deductions are specific expenses that taxpayers can list on their tax return to reduce their taxable income instead of taking the standard deduction.
Common itemized deductions include mortgage interest, state and local taxes (capped at $10,000), charitable donations, certain medical expenses that exceed a percentage of your income, and some casualty or theft losses.
To benefit from itemizing, your total eligible expenses must be greater than the standard deduction for your filing status.
Itemizing deductions will increase your refund only if your itemized costs exceed the standard deduction; receipts are required (good records are essential). Not everyone is allowed to itemize, but most taxpayers can. If you file certain returns like married filing separately, you will only be allowed to itemized if the other spouse does not take the standard deduction.
Itemizing can be especially beneficial for homeowners, high medical-expense households, and those who make large charitable contributions.
Overall, itemized deductions allow you to lower your taxable income by claiming the actual qualifying expenses you paid throughout the year.
For more information click in this link: IRS.gov