Search Ad
A search ad is the most common form of advertising with AdWords. It shows up on the search engine after a person makes a search related to a keyword that is designated in the same ad group. At the time of this writing, a text ad on the Google Search Network includes two headlines of thirty words each, a description of 80 words, a link that will take the person to a landing page when clicked, and various optional extensions. Search ads are frequently used for selling products, however, they are not limited to that. All a search ad does is send people who make a search relevant to your organization from the search engine to your website. If there is something on your website you want more people to see, you can promote it.
Read Google’s definition.