By default, when a user enters more than one word for a keyword search the results will contain assets that contained ANY of the words. This is usually ok, as the search results will be ordered according to relevancy, so those assets containing all (or more) of the keywords will be shown first.
However, you can change this behaviour so that the search only returns assets that contain ALL keywords by editing the property called ‘default-search-operator‘ in ApplicationSettings.properties (see how to change the settings file).
To have the search results return assets that contain ANY of the keywords, the setting should be:
To have the search results return assets that contain ALL of the keywords, the setting should be: