A sole proprietorship is an automatic classification if a formal business entity is not created for a business.  The name is fancier than the ultimate structure because a sole proprietorship simply means that the business and the owner are one in the same and there is no legal entity that holds the business and its assets.  All liabilities and obligations of the business are liabilities of the owner of the business.  For Silicon Valley technology companies, the sole proprietorship is not common and not a recommended structure.