What is a line chart?

The line chart is a versatile and useful chart type, and so should be available in pretty much any data visualization tool you choose. Basic line charts where one or more lines are plotted on a single axis should be common, but advanced options like dual axes may not be present or require additional data work to set up.

What is an extension to a line chart?

An extension to the line chart involves the addition of shading between the line and a zero-baseline, called an area chart. The area chart can be considered a hybrid of the line chart with the bar chart, since values can be read from not just their vertical positions, but also the size of the shaded area between each point and the baseline.

What is a special use case for a line chart?

A special use case for the line chart is the sparkline. A sparkline is essentially a small line chart, built to be put in line with text or alongside many values in a table. Because of its small size, it will not include any labeling.

Should a line chart go through all points?

In a standard line chart, each point is connected to the next with a straight line segment, from first to last. However, there may be the aesthetic temptation to try and link all of the points smoothly, fitting a curve that goes through all of the points at once. You should absolutely resist this temptation!