Text to Search For: Here is where you type what you are looking for, for example Hubble Telescope.
Boolean: Using the above example, if this option is set to AND, then the search engine will look for pages that contain both the words Hubble AND telescope. If this option is set to OR, then the search engine will look for pages that contain either the word Hubble OR telescope.
Case: If the case is set to InSensitive, it tells the search engine to ignore whether or not words are capitalized. In this scenerio, Hubble will yield the same results as the word hubble. If you set the case to Sensitive then it searches for the exact word(s) you type, specifically if they are capatialized or not. With the case set to Sensitive, the word Hubble and hubble will yield totally different results.