What is hv in chemistry?

The sunlight represent in photochemical reactions denoted as 'hv' says that a photon, is proportional to its frequency (v) by a constant factor (h) known as Plank's Constant. Organic Chemistry has different reactions for each compound. hν, light, in chemistry shorthand; Vickers Hardness, a hardness test. Note: the use of the notation hv = light (energy), compares to D = heat (thermal energy). Einstein explanation was that light had the characteristic of a particle (photon) with the photon energy of E=hv. in organic chemistry, I also see "hv" over the reaction arrow for rxns that use high energy light, like UV is "hf" and "hv" the same thing? ie does.