Augmented Reality (or AR for short) is about adding all sorts of content, such as images, videos or 3D objects to reality. And it looks like this content is a part of your reality.
On Wikipedia you can find this definition:
“Augmented reality (AR) is an interactive experience of a real-world environment where the objects that reside in the real-world are “augmented” by computer-generated perceptual information.”
“Augmented reality (AR) is an interactive experience of a real-world environment where the objects that reside in the real-world are “augmented” by computer-generated perceptual information.”