The sector and country. Private profit-making businesses are different from government-owned bodies. In some countries, certain businesses are legally obliged to be organized in certain ways.
Limited liability.Corporations, limited liability partnerships, and other specific types of business organization protect their owners or shareholders from business failure by doing business under a separate legal entity with certain legal protections. In contrast, unincorporated businesses or persons working on their own are usually not so protected.
Tax advantages. Different structures are treated differently in tax law, and may have advantages for this reason.