"Equity" means ownership. Anyone who holds one share of XYZ company owns a portion of the company. The word 'Derivative' in Financial terms is similar to the word Derivative in Mathematics. In Maths, a Derivative refers to a value or a variable that has been derived from another variable. Similarly a Financial Derivative is something that is derived out of the market of some other market product. Hence, the Derivatives market cannot stand alone. It has to depend on a commodity or an asset from which it is derived. The price of a derivative instrument is dependent on the value of the asset from which it is derived. The underlying asset can be anything like stocks, commodities, stock indices, currencies, interest rates etc.