By default, all searches will find results that contain all of the search terms you specify. Linklogs are the only exception, where results containing all of the search terms will be returned first, followed by results containing some of the search terms.
Use quotation marks (" ") around the keywords to find the exact phrase. For example searching for "apple juice", will only return results with the exact apple juice phrase, not results that simply contain both the words apple and juice.
Use the minus (-) operator to exclude any words from your search results. For example -apples juice, will include search results with the word juice but without the word apple. The plus (+) operator works by including the word instead, this is the default behavior. Operators are only supported for Web, news and images searches.
Use site:site_name to query for results on a specified site only. For example, site:wikipedia.org apples, will only include search results for the word apple within the wikipedia site. Site search is only supported for Web, news and images searches.
Using certain hint words will affect your search results. For example, using words like video, movies, film, etc. will generate results containing videos, while using words like image, pictures, icon, jpeg, etc. will generate results containing images. Linklogs also provide "hints" to other results based on previous queries. For example, a linklog that contains a video may provide the hint "video" so that general results will contain videos as well. Likewise, a linklog containing local results for "restaurants in Miami Beach" will provide that hint so that general results will contain local results for the query.