A radar chart is a way of showing multiple data points and the variation between them.
They are often useful for comparing the points of two or more different data sets.
A line chart is a way of plotting data points on a line.
Often, it is used to show trend data, and the comparison of two data sets.
Pie & Donut Charts
Pie and doughnut charts are probably the most commonly used chart there are.
They are divided into segments, the arc of each segment shows the proportional value of each piece of data.
Polar area charts are similar to pie charts, but each segment has the same angle - the radius of the segment differs depending on the value.