Keyword Targeting
Keyword targeting is a type contextual targeting that allows you to limit the pages where your ads will display to only those pages where the keywords and phrases that you define exist.
A common use case for Keyword targeting is in conjunction with a Broad targeting audience. With this combination it is possible to target all users in a country, then leverage Keywords to reach those users who are browsing content that contains your target keywords and phrases. Other targeting controls like contextual categories or locations can also be used to further refine the users you will target.