SERP
SERP stands for search engine results page: the page returned in response to a query. A modern SERP is assembled from several systems — organic results, featured snippets, knowledge panels, local packs, ads and AI summaries — rather than being one ranked list.
The acronym survives from a time when the page really was ten links. Today the composition varies by query type more than by anything else: a navigational query returns one dominant result, a local query returns a map pack, a definitional query often returns a featured snippet or an AI summary above everything else.
Each block has a different source. Organic results come from the web index. Knowledge panels come from an entity graph. Local packs come from business profiles. Ads come from an auction. You cannot rank a web page into a knowledge panel, because it is not the same system.
This is why “what position do I rank” is a weaker question than “what does this query’s results page actually look like, and how much of it is available to organic results at all”. For some queries the honest answer is: very little, and the click-through you would expect from position one does not exist.