There are many different ways to conduct person businesses, but many businesses are categorized by market. Some businesses are small and aimed at a single sector, while others happen to be large corporations that amount several sectors. A great example of this would be the retail giant Walmart or Apple. Firms define the businesses by simply industry, which include mattress development, advertising, and real estate. Web based defined by the type of trades they conduct. ExxonMobil conducts business by providing oil to its customers.