FICO scores are the most widely used credit scoring models, preferred by over 90% of lenders. They're calculated based on payment history, credit utilization, length of credit, new credit accounts, and credit mix. Scores range from 300 to 900, with various versions like FICO 8, 9, 10, and 10T offering different features. FICO scores are a subset of credit scores, which include other models like VantageScores. FICO's dominance is due to its historical presence and continual updates to reflect credit trends.