This document provides an overview of intelligent user interfaces and adaptive systems. It discusses key concepts like agents and intelligent agents. It also describes different types of agent models and environments. The benefits of user adaptivity are outlined as supporting tasks, information acquisition, and tailoring. Challenges to usability are discussed along with strategies to address tradeoffs. Methods for collecting user data both explicitly and implicitly are covered. The document concludes with the growing need for adaptivity given diverse users, contexts and information.