Some bakers disagree about this, but nearly all breads and pastries will perform equally well with any of the available yeast products (fresh, active dry, quick rise, or instant). Active dry yeast, developed about 150 years ago, is sold in sealed, foil-lined packets. But in the packaging process, about 25% of the yeast cells die off, releasing a small amount of glutathione, which causes relaxation of gluten (this makes it a good yeast for pizza dough, but it’s not ideal for all dough products).
Instant yeast, also called quick rise or rapid rise, came along about 30 years ago and has become more popular as its availability has increased. Because none of the yeast cells die during packaging, it requires 25% less instant yeast than active dry yeast to leaven a loaf. The biggest advantage of instant yeast is that it dissolves directly in dough without having to be hydrated in warm water the way active dry yeast often does. (The mini baguette recipe uses active dry yeast without first hydrating it, but it works in this case because the dough is exceptionally wet.)
Fresh yeast, also called compressed or cake yeast, is sold refrigerated in foil-wrapped blocks and cubes. It’s a moist product and has a limited shelf life of about three weeks, even if refrigerated. It is also harder to find for home baking. Professional bakers have traditionally liked this type of yeast because it’s what they learned to bake with, but many of them are now switching to instant yeast because of its extended shelf life and ease of use.