A croissant’s laminated yeast dough is described as sitting between bread and puff pastry.
That description reflects the croissant’s hybrid structure. Like bread, croissant dough contains yeast and undergoes fermentation, which expands the dough and contributes to its tender, airy interior. Like puff pastry, it is built from alternating layers of dough and butter created by rolling and folding.
The comparison is useful but not an exact claim that croissants are simply bread or puff pastry. Traditional puff pastry is generally unleavened: its lift comes mainly from steam separating butter and dough layers. Croissants receive lift from both steam and yeast fermentation. Their dough is also enriched with ingredients such as butter, sugar and sometimes milk or eggs, giving it a richer flavor than ordinary bread dough.
Croissants usually have fewer, thicker layers than classic puff pastry because yeast-generated gas bubbles can disrupt very thin gluten sheets. This helps create the open, irregular crumb associated with a well-made croissant. The French category viennoiserie captures this middle ground: baked goods with bread-like dough and pastry-like richness or layering.