Fewer vs Less
Fewer versus less is a debate in English grammar about the appropriate use of these two determiners.
Linguistic prescriptivists usually say that fewer should only be used with plural countable nouns, and that less should be used only with uncountable nouns.
Linguistic descriptivists describe real (past and current) usage, in which the word less is used with both plural countable nouns and uncountable nouns. While the prescriptive rule for the use of the word fewer is followed in practice, the traditional rule for the use of the word less is often not.