A stock market index measures the performance of a segment of the stock market. It is calculated based on the prices (and often market capitalization) of the companies which belong to the index.
Global indices are a benchmark of the international stocks performance. MSCI World, for example, consists of leading companies from developed countries all over the world.
The Dow Jones Industrial Average index (DJIA) is one of the oldest and most well known indices worldwide. In the beginning the index was composed of industrial stocks (hence the name), but today its constituents are thirty leading U.S. companies from various industry sectors.
In Europe, the most popular country indices are FTSE 100 (UK), CAC 40 (France) and DAX 30 (Germany). Also, the Euro Stoxx 50 index, composed of the Eurozone blue chips, is traced by global market participants.
In Asia, the main indices are, among others, Nikkei 225 (Japan) and the Shanghai Stock Exchange Composite index (China).