The ultimate physics personality test! On the left, we have E=hf (energy equals Planck's constant times frequency), while on the right, it's E=hν (literally the same equation, just using the Greek letter nu instead of f).
This is basically the physics equivalent of people who say "to-may-to" versus "to-mah-to" but for quantum physics! Both equations represent the same thing—the energy of a photon—but physicists are hilariously divided on which notation to use.
I'm definitely an E=hf person myself. Greek letters are just showing off! 😂