Ambient intelligence is an emerging discipline that brings intelligence to everyday environments through hidden interfaces that recognize users and adapt to their needs. It is built on technologies like ubiquitous computing, communication and intelligent user interfaces. The key steps involve sensing a user's environment and activities, reasoning to interpret context and predict needs, and acting by automating systems or providing notifications. Applications include smart homes, healthcare, transportation, education and more. Challenges remain around privacy, interoperability, reliability and resource constraints.