Mol stands for molecule. Itās the unit to describe the density of gasās, liquidās or in our case, light.
PPFD means photosynthetic photon flux density and the unit itās measured in is micomol per m² per second.
PPF means micromol per second (so we only measure the light output but not the density.)
DLI means mol per m² per day
So the short answer is, PPFD=Micomol per m² per s
and thatās what he means. Itās basically the same. He only said micomol but he means micomol per m² per s, or in other word PPFD.
Micromol is just the unit we measure our lights with. PPFD is not a mathematical unit it just means photosynthetic photon flux density.