FAIR (Factor Analysis of Information Risk) is a framework for measuring and analyzing information risk in a logical and quantitative way. It consists of (1) an ontology that defines the factors that contribute to risk and their relationships, (2) methods for measuring these factors, and (3) a computational model that calculates risk by simulating the relationships between measured factors. FAIR aims to provide an objective, evidence-based approach to risk analysis and avoid common pitfalls like inaccurate models, poor communication, and focus on worst-case scenarios. It measures factors like threat frequency, vulnerability, and loss magnitude on quantitative scales to determine overall risk.