The North American Industry Classification System (NAICS pronounced Nakes) is the Census Bureau’s “system for classifying business establishments. It is the first economic classification system to be constructed based on a single economic concept. Economic units that use like processes to produce goods or services are grouped together.” The system is hierarchical with more broad industries at the top of the numerical range. More specific industries have more numbers.
Industry information can be obtained through a variety of types of sources.
Market Research Reports--These are an excellent source for industry information. Market research reports will often cover narrower industries than a traditional industry report. You can find a variety of market research reports in Mintel.
Trade Publications--As these are published by and for people in a particular industry, they can be rich sources of industry information. Trade publications can be found in a number of different places however, a great place to start is Business Source Premier.
Newspapers and Magazines--These can often offer very recent coverage of an industry. News articles can be a good way to find information on your topic, especially in small niche industries.