Headless components are a design pattern used to build reusable UI components focused on functionality rather than presentation, allowing developers to separate logic from the UI and create versatile components that can be styled differently as needed. In React, headless components do not dictate a specific UI but provide methods for functionalities such as sorting, filtering, and inline editing, which makes them particularly useful in creating component libraries or when the same functionality needs to be presented with different UIs. This pattern encourages the reuse of logic across different presentations through smart components, render props, or custom React Hooks, as demonstrated with an example of a countdown timer where the logic is abstracted into a headless component and various UI renderings are applied separately. The implementation of headless components can also be achieved using custom Hooks, offering a less verbose alternative to render props, enabling the reuse of the same functionality across multiple UI designs, and even allowing the possibility of publishing these components as independent NPM packages.