What does the last single quote of the sql injection query: ‘ or “1”=”1″ ‘ mean


I couldn’t fully grasp why the last single quote of the sql query: ' or "1"="1" ' is necessary. So I understand the part until the last single quote ‘. The first single quote enables to inject the sql and the or "1"="1" part enables the query to always return true. However, I don’t understand why the last single quote is necessary to inject the sql.