A search result is a single entry in the list a search engine returns for a query. The full page of these entries — the SERP — now blends unpaid organic links, paid ads, and rich features such as AI Overviews, People Also Ask, and local map packs.
These result types compete for the same limited screen. Search "best running shoes for flat feet" and you may meet an AI Overview, a shopping carousel, and a People Also Ask block before the first organic link — which on a phone can sit two full scrolls down. Increasingly the answer appears on the results page itself, so the user never clicks through; these zero-click searches now account for a large share of queries. Knowing which features own a given SERP tells you what visibility is even winnable, and shapes the SEO approach for that page.