When to use a line chart

A line chart, also called a line graph or a line plot, unites a series of data points using a line.
Line charts are commonly used with continuous data in data visualization to show; they are handy for depicting:

• A trend of continuous data over time.
• A flow of continuous data set
• A comparison of multiple continuous data
• A relationship of continuous data

Remark
If you are not familiar with data types, feel free to check out the Continuous Data Type 101 and Categorical Data Type 101.

When a line chart is used

Trend

The line chart below displays the trend of the NASA budget as a percentage of the US Federal budget from 1958 to 2021.

Flow

The demo below displays the flow of the metabolic provenance of energy over 70 hours.

Comparison

The line chart displays the operating systems trends since 2004, and where users can compare the different trends.

Relationship

The demo below illustrates the strong correlation between income distribution and homicide rates. The data was collected from the entire world and covered the years from 1965 to 1994. Similar studies were conducted and concluded that income inequality has a significant and positive impact on crime rates.

A line chart is easy to create, read, and understand. A line chart is a practical and very popular chart for accessibility.