Simple chart analysis can help identify support and resistance levels. When prices move out of the trading range, it signals that either supply or demand has started to get the upper hand. If prices move above the upper band of the trading range, then demand is winning. If prices move below the lower band, then supply is winning. The price chart is an easy to read historical account of a security's price movement over a period of time.
Charts are much easier to read than a table of numbers.
On most stock charts, volume bars are displayed at the bottom. Past and present volatility. Historical volume or trading levels. Relative strength of a stock versus the overall market. Some analysts use fundamental analysis to decide what to buy and technical analysis to decide when to buy.