What does SERP mean?

SERP stands for Search Engine Results Pages. Whenever a consumer is searching for the answers to their questions, it returns a page full of results which match the searchers query. This page full of results is called the Search Engine Ranking Page. It is important because it gives your audience a chance to get acquainted with your website. The search query ( the keyword you have typed into the search engine ), organic links, and sponsored links are the main components of the SERPS. 
SERP is unique for each different search query based upon the keywords and phrases used by the searchers.