Volume is the number of shares traded in a given day
The Average Volume for a stock tracks the typical trading volume for a certain stock. The volume for a stock tracks the amount of shares that exchange hands on a particular day and is a measure of activity.
Volume is frequently used as an indicator in technical analysis as it measures whether the markets have made a strong price decision in one direction or the other. The greater the volume, the more people who are behind a stock's movement in one direction or the other.