Suppose you are researching a topic that is made up of multiple words, like "Spice Girls." (Because someone somewhere would actually research that.) If you go to JSTOR and type in the two words "spice" and "girls" by themselves, you are telling the search engine that you want it to pull up any results with either or both of those words. As you can imagine, this would grievously increase your research time by forcing you to slog through totally irrelevant results. However, if you put quotation marks around the phrase "Spice Girls," now you are telling the search engine that you only want results that have those two words in that exact order. This significantly reduces the number of results you have to wade through. (Some databases want you to use parentheses instead of quotation marks, while others will accept either symbol.)