volatile

Volatile is an adjective with multiple related senses in science, technology, and everyday language. Its core idea is propensity to change rapidly, whether by converting from a liquid to a gas or by fluctuating unpredictably in other contexts. The term derives from Latin volatilis, meaning “flyable” or “that can fly away.”

In chemistry and physics, volatility describes how readily a substance vaporizes. Substances with high volatility have high vapor pressures at a given temperature and low boiling points; they form vapors easily at room temperature. Volatility is central to the behavior of volatile organic compounds (VOCs), which can contribute to air pollution and pose health hazards. Common volatile liquids include gasoline, acetone, and ether. The concept is important for distillation, evaporation rates, and safety planning around flammable liquids.

In computing, volatile memory is computer memory that loses its stored information when power is removed. RAM (random-access memory) is volatile, in contrast to non-volatile memory such as flash or ROM, which retains data without power. Volatile storage requires continuous power to preserve data, affecting system design, caching, and data integrity strategies.

In finance, volatility is a statistical measure of the dispersion of returns for a given security or market index. Highly volatile assets exhibit large price swings over short periods, increasing risk and potential reward. Market volatility is often estimated by standard deviation or models such as the VIX.

Etymologically and in common usage, volatile can also describe people or situations that are unstable and prone to sudden changes, emphasizing unpredictability.