Bubble Charts are a convenient way for graphical representation of multi-dimensional data. The data points are displayed as circles (or other shapes) with variable parameters (size, position etc.) that depend on the input data. For example a 2D Bubble Chart can represent a data set with up to 4 dimensions: X position, Y position, Size and Color.
2D Bubble Chart
XY Scatter bubble charts allow presentation of freely distributed values along X and Y axes.
XY Scatter Bubble chart