What does "sift" mean in baking?

In baking, the term "sift" refers specifically to the process of passing dry ingredients, such as flour or powdered sugar, through a sieve or sifter. This action serves multiple purposes: it aerates the ingredients, which helps to create a lighter texture in baked goods, and it also combines them more evenly. When ingredients are sifted, any clumps are broken up, ensuring a smoother consistency that facilitates better mixing with wet ingredients later on.

In contrast, mixing wet and dry ingredients together involves combining ingredients that are already prepared rather than manipulating the dry ingredients in their raw form. Rolling out dough to a specific thickness pertains to the preparation of pastry or other doughs, while cutting food into small pieces relates to chopping rather than any mixing or aerating process associated with sifting. Thus, the correct answer captures the essence of what it means to sift in the context of baking.