Contextual targeting involves the use of linguistic factors to control the placement of advertising material.
The advertisements are selected and delivered by automated systems, taking into consideration the context of a user's search or browsing behavior.
[2] Contextual ads are commonly perceived as less irritating than traditional advertising, therefore influencing users more effectively.
[citation needed] It works by providing webmasters with JavaScript code that, when inserted into webpages, displays relevant advertisements from the Google ad inventory.
Relevance is calculated by a separate Googlebot that indexes the content of a webpage.