This document discusses key concepts related to volatility, share capital, and indices. It defines volatility as a measure of uncertainty or risk about changes in a security's value, with higher volatility meaning a wider range of potential price movements. It also defines types of volatility like historical and implied. The document discusses India's volatility index (VIX) and how it can help gauge market sentiment. It defines various types of share capital like authorized, issued, subscribed, and called-up share capital. It also provides a definition of indices as imaginary portfolios representing a market or portion of it.