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.