Here’s a brief description of each business structure and potential tax deductions:

1. Sole Proprietorship: This is the simplest form of business, owned and operated by one person. The owner reports business income and expenses on their personal tax return. Common deductions include home office, supplies, and business travel.

2. 
   
   LLC (Limited Liability Company): An LLC provides liability protection to its owners (members). It can be taxed as a sole proprietorship, partnership, or corporation. Deductions may include business expenses, health insurance premiums, and retirement contributions.

3. S Corporation: An S Corporation allows income, losses, deductions, and credits to pass through to shareholders for federal tax purposes. Common deductions include salaries, benefits, and business expenses.

4. Nonprofit Organization: A nonprofit is organized for charitable, educational, or similar purposes. It is exempt from federal income tax. Deductions for nonprofits typically include operational expenses, fundraising costs, and charitable donations.

Each structure has unique tax benefits and obligations, so it's important to consult with a tax professional for personalized advice.