What is
Augmented reality?

AR is the technology that places digital content over reality by looking through a device.

AR

source: SparkAR - Facebook
Augmented reality describes computer technology placing digital content on top of the real world which in turn gets visible by looking through a device. This device can be a smartphone or a tablet or a more advanced headset. Face Filters which are used by Instagram and Snapchat are the most popular and best known AR applications. 
With AR becoming more and more popular, it gains the potential to change the way we communicate and interact with reality. Information can be projected into our field of view, with more games like Pokemon Go embracing and including the reality surrounding us
The way retailers deliver their products to consumers can be fundamentally changed. Trying on clothes before they are ordered, checking out what furniture might look like in our home before buying it, or ordering food after examining compelling 3D models of it would be and already is possible. Completely new ways of marketing are imaginable. Custom-tailored adds could be placed directly in your environment. Product and adds can be brought to life through visual and digital extension, thereby enhancing consumer interaction.
Ikea App. Source: Ikea
Google Maps AR. Source: Auto Bild
Pokemon Go. Source: Frankfurter Messe

GET

A NEW

FACE

In contrast to VR and MR, augmented reality has the huge advantage of being available through a standard smartphone, removing any technological barrier for both the consumer and the retailer. Most people have already used an AR app, at least in the form of a face filter.
For this technology to work, algorithms are needed which recognize targets and track these in the real world, so that a digital object can be placed in that position in real time. 
Aside from facial recognition, images and flat surfaces can be discerned. Animations can be placed on top of images, thereby bringing the image to life; digital objects can be placed on surfaces (which goes fluently into MR).