Floridaâs tract of coral reefs has the honor of being the third-largest barrier reef ecosystem in the world. However, it could soon be a thing of the past, as the acidification of the oceanâs water is dissolving it faster than it can rebuild.
index (plural indexes or indices) 1  An alphabetical listing of items and their location. The index of a book lists words or expressions and the pages of the book upon which they are to be found. 2  The index finger; the forefinger. 3  A movable finger on a gauge, scale, etc.
Key features of indices. Indices are designed to be broad measures of performance of an asset class or a subset of that asset class. So that indices are widely adopted, the methodology used to create an index is often published to give stakeholders an understanding of how decisions governing index calculation are made.