You're very close! Electromagnetic waves differ only in their frequency and wavelength, which are directly related.

Here's why:

* Frequency: The number of waves passing a point in a given time (measured in Hertz, Hz).

* Wavelength: The distance between two consecutive crests or troughs of a wave (measured in meters, m).

Energy is directly related to frequency:

* Higher frequency waves have higher energy.

* Lower frequency waves have lower energy.

So, while energy is a key characteristic, it's ultimately determined by frequency.

Let me know if you have any other questions!