Quotation marks (" ") are used when you want to search an exact phrase of two or more words. For example, a Google search for physical therapy without the quotation marks gives nearly 1.7 billion results (as of Feb. 2023), whereas searching for "physical therapy" with the quotations marks gives 138 million results (about 8% of 1.7 billion).
Boolean operators: and, or, not. Use to either increase or decrease the scope of your search
AND is a limiting term meaning that the more words you put with AND, the few results you get.
OR is an expanding term meaning that the more words you put with OR, the more results you get.
NOT is a limiting term meaning that you are telling the search engine to deliberately eliminate keywords.
image courtesy of Ohio University Libraries