Keyword matching options help control which searches trigger an advertisement to show. There are several options: 1) Broad match – allows the ad to show for searches on similar phrases or relevant variations, which include synonyms, singular and plural forms, possible misspellings, stemmings, and other relevant variations. 2) Broad match modifier – allows the ad to show for searches that include broad match keywords or close variations of the broad match keyword. 3) Phrase match – allows the ad to show only for searches that include the exact phrase, or close variations of that exact phrase, with additional words before or after. 4) Exact match – allows the ad to show only for searches that use that exact phrase, or very close variations of the exact phrase and no other words.