What conveys a visual representation of data?
Anything that is a picture (or graph) that illustrates the interaction of the data.
There are almost endless varieties and permutations of data presentation. The most common in science is usually the simple graphic chart - although the variations with bars, lines, contours, scales and other parameters can also make them far from simple.
Graphics are used for a different reason than the underlying numbers or calculations. An effective report or presentation knows when to use which.
Visual representation of data is also notorious for being used to introduce intentional bias, so it should be used and viewed even more critically than numeric data and equations.