According to Chef Depot, in cooking, the word "aeration" typically refers specifically to the process of sifting dry ingredients, such as flour, through a fine mesh. This process incorporates air into the flour, making it lighter, while mixing ingredients evenly.
Although "aeration" refers specifically to the act of sifting dry ingredients in a culinary context, the literal process of incorporating air into something has many other culinary applications. For example, the process of beating a mixture with a wire whisk is a form of aeration intended to make it lighter; this kind of aeration is how light, fluffy whipped cream is made from dense heavy cream. The word "aeration" can also refer to what is colloquially called "letting wine breathe." Exposing wine to the air raises its temperature and helps its aromas become more readily apparent.