How it works
SERP stands for search engine results page. A modern SERP is assembled from features: ads, an AI Overview, the map pack, People Also Ask, featured snippets, images, video, shopping results and finally the organic list. Which features appear, and in what order, changes by query, by location and by device.
This matters for planning, because ranking first organically means something different on every query. On a query dominated by an AI Overview and a map pack, first organic may sit below the fold and receive a fraction of the clicks a flat SERP would send. On an informational query with no ads, the same position can bring most of the traffic.
Any keyword worth targeting should be looked at before it is chosen. What the SERP already looks like tells you what winning it would actually be worth, and which format (a guide, a local page, a video, a comparison) Google currently rewards. Ten minutes looking at the real results often saves months spent on a page that could never earn the click.