Technical analyst always focuses on volume. Actually what does it mean by volume? Normally volume is the number of share treaded in a particular day. High volume expresses the activeness of the share. For tracing the movement of volume an analyst normally use Volume bar. Now question why volume is so important? Yes volume is important because volume confirm the various chart patterns and trends. If you see price of a share is increasing without volume support then you can take it as a fake breakout and it will not sustain for long period. Assume after a downtrend price changes dramatically (5%) and volume does not increase. Will you consider it as a upward trend? No we cannot because it is a spike and we have to avoid this fake spike. we can say the trend is changing when volume will gradually increase. So volume confirms the trend and patterns.