Answer:
Intensity
Step-by-step explanation:
The graph shows different types of radiation!
The red line imples how intense the radiation is. When the line is long and spread out, it implies less intensity. When it moves up and down quickly, as you can see in the end of the graph, it implies high intensity.
We can confirm this by seeing the labels. Indeed, Radio waves are the least powerful, and gamma rays the most.
~~~Harsha~~~