You would choose to advertise on the Google Search Network if you wanted to:
reach customers browsing websites related to your business
reach customers while they’re searching for your products or services
choose the types of websites where you want your ads to show
choose from a range of ad formats, like video and image ads
Explanations:
The Google Search Network is a group of search-related websites and apps where your ads can appear. When you advertise on the Google Search Network, your ad can show near search results when someone searches with terms related to one of your keywords
A Search Network campaign may be a good option for you if you meet one or more of the following criteria:
- You want your ads to appear near Google search results
- You only want to reach customers searching for your specific product or service
Read more here: https://support.google.com/adwords/answer/2497941?hl=en