The document discusses augmented reality (AR) and provides definitions of AR from dictionaries and Wikipedia. It explores AR from a human-centered perspective, examining how AR can enhance human experiences with the world. Specifically, it looks at how AR can impact people, places, and things. Key points discussed include the need for user-centered design in AR, considering both intended and unintended users, mediating the real world carefully in AR experiences, and selecting technology that enhances senses in a way that supports natural human perception. Safety concerns with AR are also raised in the context of distracted use. The document suggests we are currently at the beginning of mainstream adoption of AR technology.