Augmented Reality (AR):can be defined as a system that fulfills three basic features: a combination of real and virtual worlds, real-time interaction, and accurate 3D registration of virtual and real objects. The overlaid sensory information can be constructive (additive to the natural environment), or destructive (masking of the natural environment). Augmented Reality is the most interesting for most people.
The idea is that a computer overlays content on the real world. An example of this is an app on your cell phone that turns on the camera and overlays information about the things and places it is pointed at. A scene might include the date of construction for the building the camera is pointed at, along with local weather information and a small map showing the location of the nearest bathroom or ShopRite.
This experience is seamlessly interwoven with the physical world such that it is perceived as an immersive aspect of the real environment in this way, augmented reality alters one’s ongoing perception of a real-world environment. whereas virtual reality completely replaces the user’s real-world environment with a simulated one. Augmented reality is related to two largely synonymous terms: mixed reality and computer-mediated reality.
The primary value of augmented reality is the manner in which components of the digital world blend into a person’s perception of the real world, not as a simple display of data, but through the integration of immersive sensations, which are perceived as natural parts of an environment. Augmented reality is used to enhance natural environments or situations and offer perceptually enriched experiences. With the help of advanced AR technologies (e.g. adding computer vision, incorporating AR cameras into smartphone applications and object recognition) the information about the surrounding real world of the user becomes interactive and digitally manipulated. Information about the environment and its objects is overlaid on the real world. This information can be virtual or real, e.g. seeing other real sensed or measured information such as electromagnetic radio waves overlaid in exact alignment with where they actually are in space.
Augmented reality also has a lot of potential in the gathering and sharing of tacit knowledge. Augmentation techniques are typically performed in real time and in semantic contexts with environmental elements. Immersive perceptual information is sometimes combined with supplemental information like scores over a live video feed of a sporting event

VIRTUAL REALITY:
Virtual Reality is the one everyone is familiar with. It has been around since the 1970’s but has been just too expensive and needed too much computing power to be practical until the mid-2000’s. VR is most often presented in a helmet or wrap around glasses that allow you to immerse yourself in a fully computer generated world which give you the impression that you’re somewhere else.
In virtual reality (VR), the users’ perception of reality is completely based on virtual information.
DIFFERENCE BETWEEN AR AND VR
In augmented reality (AR) the user is provided with additional computer generated information that enhances their perception of reality. For example, in architecture, VR can be used to create a walk-through simulation of the inside of a new building; and AR can be used to show a building’s structures and systems superimposed on a real-life view. Another example is through the use of utility applications. Some AR applications, such as Augment, enable users to apply digital objects into real environments, allowing businesses to use augmented reality devices as a way to preview their products in the real world.Similarly, it can also be used to demo what products may look like in an environment for customers, as demonstrated by companies such as Mountain Equipment Co-op who use augmented reality to allow customers to preview what their products might look like at home through the use of 3D models.
