A Radar Chart (also called a Spider Chart or Web Chart) displays multidimensional data on a circular graph. Each axis represents one variable, and values are plotted as a point on each axis and connected with lines. These variables are represented on axes that radiate from a central point. 

Key features and uses of radar charts: 

Multiple variables:

Radar charts allow for the comparison of multiple variables (three or more) on a single chart. 

Radial axes:

Each variable is plotted on a separate axis that extends from the center. 

Polygon formation:

The data points on each axis are connected to form a polygon, which can help visualize the overall distribution and patterns of the data. 

Comparison:

Radar charts are useful for comparing different datasets or different categories within a dataset across multiple variables.

Performance visualization:

They are often used to visualize performance, such as in skill analysis of employees or sports players, or for product comparisons.

Identifying strengths and weaknesses:

Radar charts can help quickly identify which variables are scoring high or low within a dataset, highlighting areas of strength or weakness.

Outlier detection:

They can also be useful for spotting outliers or unusual values within the data.

Clarity and clutter:

While effective for comparison, radar charts can become cluttered and difficult to read if too many variables or data series are included.

In essence, a radar chart is a way to visualize how different items or groups perform across multiple characteristics or variables, making it easy to spot patterns and differences in a concise way. 

 Radar Chart Example using Chart.js