These are paid advertisements via Google AdWords. You can differentiate these from organic (non-paid, earned) results because of the tiny yellow “ad” icon. Normally, you will also see paid ads at the top of the SERP as well. In this book, we are only talking about SEO for organic search results, not advertising through search engines. But it is important to understand the difference as a user, and as a search engine optimizer, as they can both be valuable.
In an effort to make the user search experience easier and more direct, Google created SERP features, on-page content that gives users answers to their queries without requiring them to click into an organic result. Although on-page SERP features are optimal for the user, they can make it harder for marketers to get noticed in organic search results, even when they're ranking #1.
Search engine optimization (SEO) is the process of affecting the online visibility of a website or a web page in a web search engine's unpaid results—often referred to as "natural", "organic", or "earned" results. In general, the earlier (or higher ranked on the search results page), and more frequently a website appears in the search results list, the more visitors it will receive from the search engine's users; these visitors can then be converted into customers. SEO may target different kinds of search, including image search, video search, academic search, news search, and industry-specific vertical search engines. SEO differs from local search engine optimization in that the latter is focused on optimizing a business' online presence so that its web pages will be displayed by search engines when a user enters a local search for its products or services. The former instead is more focused on national or international searches.