A line chart or line graph is a type of chart which displays information as a series of data points called ‘markers’ connected by straight line segments. It is a basic type of chart common in many fields. It is similar to a scatter plot except that the measurement points are ordered (typically by their x-axis value) and joined with straight line segments. A line chart is often used to visualize a trend in data over intervals of time – a time series – thus the line is often drawn chronologically. In these cases they are known as run charts.
An open-high-low-close chart (also OHLC chart) is a type of chart typically used to illustrate movements in the price of a financial instrument over time. Each vertical line on the chart shows the price range (the highest and lowest prices) over one unit of time, e.g., one day or one hour. Tick marks project from each side of the line indicating the opening price (e.g., for a daily bar chart this would be the starting price for that day) on the left, and the closing price for that time period on the right. The bars may be shown in different hues depending on whether prices rose or fell in that period.
A candlestick chart (also called Japanese candlestick chart) is a style of financial chart used to describe price movements of a security, derivative, or currency. Each “candlestick” typically shows one day; so for example a one-month chart may show the 20 trading days as 20 “candlesticks”.
It is like a combination of line-chart and a bar-chart: each bar represents all four important pieces of information for that day: the open, the close, the high and the low. Being densely packed with information, they tend to represent trading patterns over short periods of time, often a few days or a few trading sessions.
Candlestick charts are most often used in technical analysis of equity and currency price patterns. They appear superficially similar to box plots, but are unrelated.