Andy M.
Certified Pretend Chef
...
Phylo are very dry and super thin, single sheet. These are made with an oil rather than a fat...
...Phylo doesn't 'puff' but does have multiple (and delightful) layers of crunch. It really depends on the recipe and the end result you are looking for.
Oil is a fat.
Phyllo with butter between the layers does puff up some but not as much as puff pastry.