DataForSEO is an API platform used for collecting extensive keyword research and SERP analysis data. Its functionalities include generating keyword suggestions based on intent, fetching search volume, competitiveness, CPC, and trend data, as well as providing Keyword Difficulty information. The API is noted for providing a list of the top 1000 websites based on the number of ranked keywords in their database, which can be used to manually classify the holistic intent of ranking domains in SERP analysis. It is also employed for scraping detailed SERP features to answer critical questions about competition, query structure, and search intent.