Sector
The most widely used framework divides the stock market into eleven sectors: Energy, Materials, Industrials, Consumer Discretionary, Consumer Staples, Health Care, Financials, Information Technology, Communication Services, Utilities, and Real Estate. This system — the Global Industry Classification Standard, or GICS, developed jointly by MSCI and S&P — gives every listed company a home. Knowing a company's sector tells you immediately what economic forces tend to drive its revenue.
Sectors matter for reading market data because they move differently. When oil prices rise, Energy sector stocks often benefit while airlines (Industrials or Consumer Discretionary, depending on classification) face higher costs. Tracking sector performance separately — rather than just watching an overall index — lets analysts pinpoint which parts of the economy markets are rewarding or punishing at a given moment. The stocks page surfaces these moves in real time.
A common confusion is the difference between a sector and an industry. In the GICS structure, sectors are the broadest level; each sector contains multiple industry groups, which break down further into industries and then sub-industries. For example, "Information Technology" is the sector; "Semiconductors" is an industry within it. Sectors also overlap thematically with the cyclical versus defensive distinction, though that split crosses sector boundaries rather than mapping neatly onto them.