How does Google handle double hyphens?

 Google treats double hyphens (--) as a signal to exclude a particular word or phrase from search results. This is known as a "negative keyword" or "negative search term."

When you include a double hyphen before a word or phrase in your search query, Google will exclude any search results that include that word or phrase. For example, if you search for "dog --cat," Google will return search results for "dog" but exclude any results that include the word "cat."

Double hyphens are typically used in conjunction with other search operators, such as quotation marks, to refine search results and exclude specific terms. For example, you could search for "dog food" --canned --wet to find search results for dog food that are not canned or wet.

It's important to note that double hyphens can only be used to exclude single words or phrases. If you want to exclude a longer phrase or multiple words, you can use quotation marks to search for an exact phrase and include a minus sign before each word you want to exclude. For example, you could search for "dog food" -"canned food" -"wet food" to exclude all results that mention canned or wet food.

Overall, double hyphens are a useful search operator for excluding specific terms from search results and refining your search queries in Google.