Final answer:
The line of code is a single line comment in programming, used to annotate code without affecting its execution. In many languages, the // denotes that the line is commented out.
Step-by-step explanation:
The line of code // the loop function runs over and over again forever is a single line comment in programming. Comments are used by programmers to explain and annotate their code to make it easier to understand. They don't affect the execution of the code. In many programming languages, such as JavaScript, C, C++, and Java, comments that start with // are single line comments, which means they only comment out the line they are on.