**Bivariate charts** display information about the relationship between *two* variables. This includes scatterplots and line graphs.

When you have continuous data, you can get a sense of the data's density around values using a **histogram**. A histogram breaks your data up into **bins**, so that values falling within each bin are grouped together. Then the number of values (i.e. the frequency of values) in each bin is plotted out like a bar chart. This helps provide a sense of how the data is distributed.

**Scatterplots** plot out each individual data point (according to two dimensions) and can provide intuitions into correlation of the plotted dimensions, amongst other things.

- OpenIntro Statistics. Second Edition. David M Diez, Christopher D Barr, Mine Ã‡etinkaya-Rundel.