1. The manufacturing or technically productive enterprises in a particular field, country, region, or economy viewed collectively, or one of these individually. A single industry is often named after its principal product; for example, the auto industry. For statistical purposes, industries are categorized generally according a uniform classification code such as Standard Industrial Classification (SIC).
2. Any general business activity or commercial enterprise that can be isolated from others, such as the tourist industry or the entertainment industry.
business tax
Source: http://www.businessdictionary.com/definition/industry.html