So Google has two different ad networks you should know about.
Of course, there’s the Display Network, but there’s also the Search Network.
While the Display Network focuses on visual ads, the Search Network focuses on text-based ads. You’ll see Search Network ads in the Google Search results with a small ad tag.  Again, display ads will show up on other Google properties like YouTube and Gmail, and in its network of websites.
The way you target your audience with these ads is different, too.  Search ads mainly rely on keywords to determine when your ad will show up. So if someone looking for gourmet cookies searches for the phrase “gourmet cookies,” ads related to that keyword will show up. With display ads, you’re focusing not on keywords but on different audience segments.