"Hooked" is a book by Nir Eyal that explores how products can create habits in users. It outlines a framework called the Hook Model, which consists of four key components: Trigger, Action, Variable Reward, and Investment. This model helps businesses understand how to design products that keep users engaged and coming back. The book emphasizes the importance of understanding user behavior and psychology in product development. By applying the principles in "Hooked," companies can create more compelling experiences that encourage habitual use, ultimately leading to increased customer loyalty and satisfaction.