Excluded category names are not indexed as keywords for the product and are not included in search phrase suggestions. This is useful for combination categories that have subcategories with distinct products.
However, don't exclude categories if they contain products that are not assigned to subcategories or additional categories that can be indexed. There might also be combination categories that you don't want to exclude, such as headphones and earbuds, where you want related products to appear. For example, if a customer searches for headphones, you might want lower-cost earbuds to also appear in the search.