Scatter charts or scatterplots are very popular in data science and statistics. They can be used to explore various kinds of correlations between variables, revealing trends, clusters, linear, and non-linear relationships. It's an essential tool in problem solving procedures and decision-making.
Scatter charts display the correlation between two variables by plotting their points in a system of Cartesian coordinates. Additional variables can be displayed by using different shapes and/or colors for the points.
A bubble chart is a scatter chart that uses circles with different radii to display an additional variable. It's also common to overlap scatter charts with other charts, such as line and bar charts, as to emphasize patterns and compare raw data with estimates, such as trendlines (best-fit).