Ad extensions let you make your ads more useful and relevant to users searching for information on Google. While the standard text ad format can often provide enough information for users to find what they’re looking for, sometimes some extra information helps get the best response.
For example, when you’re trying to describe a product, including a picture could make the message more relevant and valuable. Or when trying to describe a location, an ad that only contains text can be confusing. In this case, having a map would make it much easier for the user to find you.
Ad extensions work with your existing text ads, so there’s no need to change your keywords, bids, or ad text.