Broad match
Broad match is the default match type that all your keywords are assigned. Ads may show on searches that include misspellings, synonyms, related searches, and other relevant variations. So if your keyword is “women’s hats,” someone searching for “buy ladies hats” might see your ad.
Negative keywords
Excludes your ads from showing on searches with that term. So if you’re a hat company that doesn’t sell baseball hats, you could add add a negative keyword, designated with a minus sign (-baseball hats).
Broad match modifier
Similar to broad match, except that the broad match modifier option only shows ads in searches including the words designated with a plus sign (+women’s hats) or close variations of them.
Phrase match
Ads may show on searches that match a phrase, or are close variations of that phrase, with additional words before or after. Ads won't show, however, if a word is added to the middle of the phrase, or if words in the phrase are reordered in any way. Designated with quotation marks ("women's hats").
Exact match
Ads may show on searches that match the exact term or are close variations of that exact term. Close variants include searches for keywords with the same meaning as the exact keywords, regardless of spelling or grammar differences between the query and the keyword. Close variations here may also include a reordering of words if it doesn’t change the meaning, and the addition or removal of function words (prepositions, conjunctions, articles, and other words that don’t impact the intent of a search), implied words, synonyms and paraphrases, and words that have the same search intent. Designated with brackets, the keyword [women's hats] could show when someone searches on Google for “hats for women.”