Behaviors can encapsulate reusable functionality into components. There are two types: attached behaviors, which are static and can be used in store apps but not blended, and blend behaviors, which are blendable but not available in store apps. Behaviors help keep the MVVM pattern intact and allow reusable functionality without codebehind or view models knowing the object in use. A lab demonstrates making text draggable with attached and blend behaviors, scrolling to a selected item on click, and creating a drag and drop behavior.