Most sites offer the option of viewing a price chart in two formats: line or bar-chart. A line chart consists of a line connecting the closing prices.
A bar chart (Figure 14-4) uses a vertical line (bar) to represent one period. The bar period is typically a day, a week, or a month, depending on the time span covered. The top of the bar is the highest price for the period, and the bottom is the low. A horizontal extension to the left represents the opening price, and an extension to the right shows the closing price for the period.