Deductible business expenses are ordinary and necessary costs you incur while running your business, and they help reduce your taxable income. These expenses can include things like job supplies, equipment, rent expenses (office, warehouse, storage, equipment), utilities, advertising, business insurance, professional services, and sometimes a part of your home if you use it regularly and exclusively for business (home office).
To qualify, the expense must be directly related to your business operations and not personal. Keeping good records and receipts is very important because you can only deduct expenses that are properly documented. By claiming deductible business expenses, you lower your taxable profit, which can reduce the amount of tax you owe and help keep more of your business earnings.
For more information click in this link: IRS.gov