Bar Chart

What Does Bar Chart Mean?
A style of chart used by some technical analysts, on which, as illustrated below, the top of the vertical line indicates the highest price a security traded at during the day, and the bottom represents the lowest price. The closing price is displayed on the right side of the bar, and the opening price is shown on the left side of the bar. A single bar like the one below represents one day of trading.

Investopedia explains Bar Chart
These are the most popular type of chart used in technical analysis. The visual representation of price activity over a given period of time is used to spot trends and patterns.