Visual information (charts, graphs) helps the reader better understand what’s going on because for visual learners, can also help the reader learn more about the topic in the passage. For example in Geothermal Heating, and Cooling it shows the Primary Energy Consumption of 2010. It is easier for the reader to learn this because you can see it, by a graph.
Also little things can help you visual things, you can use your mind to paint a picture. That’s if the author has very good description, but for visual learners graphs help a lot. For example, if I were to say “The core is the last layer out of the Earth layers, and the mantle is the 2nd outermost layer”. It’s pretty hard to image because you can’t see it. You get a better understanding of what everything looks like. Also, if you weren’t to see what you’re reading about you probably wouldn’t understand it.
That is how visual information can help you better understand what everything looks like, and how it works. It is very beneficial to be able to understand/see what you’re reading about.