Summary attempts to extract the search string used by a visitor at a major search engine to find your site. This information is extracted from the referrer. The entire string is called the search phrase.
The search phrase is extracted from the referer field. When you perform a search in a web based search engine, the search phrase you typed usually appear in the URL. Thus, if someone visits your website through a search engine, his search phrase will be included in the referer field.
Two or more keywords in a specified order. When you enter multiple words enclosed by quotation marks in a search box, Compass searches for those words as a phrase (those words in that order). For example, if you search for the phrase "declaration of independence," you will only find documents with those three words in that order. But if you search for the keywords declaration of independence (no quotes), you will find documents that contain those words, but not necessarily in that order. See also criteria and Search Hints.