Search ads appear at the top of search engines like Google, Bing or Yahoo after a user enters keywords (example: laptops). Users will see 3-4 ads at the top of a Google Search with product listings ads in the right sidebar (if a keyword for a product is part of the search). Bing and Yahoo still have regular text ads on the right sidebar, but Google removed these ad positions in early 2016.
These types of ads can also be referred as Pay Per Click (PPC), Google AdWords or Search Engine Marketing (SEM). Your ad can feature 25 Characters in the Headline and 35 characters on the following two lines of description text (however, this will be changing in late 2016). Additionally, specific extensions can be added to your ads to enhance the click through rate and overall performance.
See below for examples of how these ads appear on each one of these platforms.