Search for an exact word or phrase 
"search"

Use quotes to search for an exact word or set of words on a web page. This is helpful when searching for song lyrics or a line from a book. But only use this if you're looking for an exact word or phrase, otherwise you'll exclude many helpful results by mistake.
"imagine all the people"

Exclude a word
-search

Add a dash (-) before a word or site to exclude all results that include that word. This is especially useful for words with multiple meanings, like Jaguar the car brand and jaguar the animal. 
jaguar speed -car
pandas -site:wikipedia.org

Fill in the blank
*

Add an asterisk within a search as a placeholder for any unknown or wildcard terms. Use with quotation marks to find variations of that exact phrase or to remember words in the middle of a phrase.
"a * saved is a * earned"

Search for either word
OR

If you want to search for pages that may have just one of several words, include OR (capitalized) between the words. Without the OR, your results would typically show only pages that match both terms.
world cup location 2014 OR 2018