In business, a sole proprietorship is one that has a single owner and that's not a legal entity or incorporated. The United States Small Business Administration defines it as the simplest and most common business structure. Because only one person is at the helm, that individual is entitled to all of the company's profits.
The individual is also responsible for all its debts, losses and liabilities. A scenario in which being liable can be disadvantageous to the owner if one of his or her employees was involved in a business-related accident, and someone was hurt or killed. The negligence case would likely be brought against the owner and all of that individual's assets, including bank accounts and home.