A SERP or Search Engine Results Page, is the web page presented to a user when they search a query into a search engine. Every SERP is unique, based on the searcher's location, their browsing history and their settings.
SERPs are important for SEO because the more visible your content is, the more likely it is going to receive more traffic. Google wants to provide the most important results and show answers as quickly as possible to help searches.
SERPs consists of three types of search results, Organic Results, Paid Results and rich results enhanced with different features such as images, videos, rating stars etc.
These are some of the most common organic SERP's you will see on Google
Paid Results in SERPs