Autolyse: flour + water. It's not an official fermentation since it doesn't have a leavening agent
Sponge: A representative version of the dough with the entire amount of yeast (less than direct dough)
Biga: A more dense version of the dough with the entire amount of yeast (less than sponge)
Poolish: a super hydrated starter with the entire amount of yeast (same as biga)
