The terms industry and sector are often used interchangeably to describe a group of companies that operate in the same segment of the economy or share a similar business type. Although the terms are commonly used interchangeably, they do, in fact, have slightly different meanings. This difference pertains to their scope; a sector refers to a large segment of the economy, while the term industry describes a much more specific group of companies or businesses.

A sector is one of a few general segments in the economy within which a large group of companies can be categorized. An economy can be broken down into about a dozen sectors, which can describe nearly all of the business activity in that economy. For example, the basic materials sector is the segment of the economy in which companies deal in the business of exploration, processing and selling the basic materials such as gold, silver or aluminum, which are used by other sectors of the economy. Sectors also often have specific exchange-traded funds (ETFs) that track the sector, such as the Energy Select Sector SPDR Fund (XLE).


What's The Difference Between Industry And Sector?

An industry, on the other hand, describes a much more specific grouping of companies with highly similar business activities. Essentially, industries are created by further breaking down sectors into more defined groupings. Each of the dozen or so sectors will have a varying number of industries, but it can be in the hundreds. For example, the financial sector can be broken down into industries such as asset management, life insurance, or brokerage.

When breaking down an economy, the first groups are sectors which describe a general economic activity. Then all of the companies that fall into that sector are categorized further into industries where they are grouped only with companies with which they share very similar business activities. This is not the end, however. Industries can be further sub-categorized into various, more specific groupings.

It should be noted that you may find situations in which these two terms are reversed. However, the general idea remains: one breaks the economy down into a few general segments while the other further categorizes those into more specific business activities. In the stock market, the generally accepted terminology cites a sector as a broad classification and an industry as a more specific one.

To learn more, check out the Industry Handbook, and Sector Rotation: The Essentials.