This document discusses adaptive and adaptable interfaces. It defines adaptive interfaces as interfaces that automatically change based on user behavior or context without user input. Examples mentioned include adaptive hyperlinks that change based on user interests and adaptive menus that rearrange options based on predicted user needs. Adaptable interfaces are defined as interfaces that users can manually change and customize to fit their preferences or tasks. The document contrasts fine-grained versus coarse-grained levels of adaptability and mentions examples of adaptable interfaces that allow customizing options or preferences. It also references studies on adaptive techniques like using eye tracking for adaptation and the tradeoffs between prediction accuracy and adaptation in user interfaces.