Chartjunk

Chartjunk is basically all the extra stuff that is added to a chart or graph that makes it harder to read and understand. It's like putting too many stickers on a picture that you can't see what's going on anymore.

For example, if someone draws a picture of a cat, but then adds a bunch of flowers and rainbows and glitter all over it, it becomes harder to tell that it's a cat. Similarly, if someone creates a graph about how much candy people eat, but then adds unnecessary shapes or colors, it becomes harder to figure out how much candy people are actually eating.

In short, chartjunk is anything that takes away from the main point or message of a chart or graph. It's important to keep your charts and graphs simple and easy to understand so that people can quickly see and understand the information you're trying to convey.