Execution highlighting reduces the speed of execution and displays data bubbles that move along the wires, revealing the data that each node receives when it executes.
When you begin debugging a program, you may not be able to identify which part of the code introduces the incorrect behavior. To gain a better idea of how data progresses and changes as it flows through the code, you can use execution highlighting.
Execution highlighting helps you detect the following kinds of unintended behavior:
You can turn on execution highlighting by clicking the Highlight execution button on the document toolbar.