Augmented reality (AR) is the live, direct, or indirect physical display of the real-world environment and its contents, enriched by computer-generated sound, image, graphics and GPS data. It is a computer modified and enhanced reality . AR transposes virtual objects and information onto real-world environments. Mixing of the real and virtual environments creates the augmented reality experience. AR outputs can range from single texts to the complex aircraft engine parts. In other words, It can enable the users to experience whatever they want. By their intended purposes, ARs are categorized into four types as marker-based, markerless, projection-based, and superimposition based.
With a camera and a QR-coded specific image target, the marker-based AR uses image recognition algorithms. The main purpose of the marker is showing the result when the camera sees the marker image. The simple image used for this category because simple image targets (such as QR code) can be easily read through pattern recognition algorithms. After the recognition of the image target, the application starts the orientation and position calculations, followed by the marker overlay on the design.
Markerless based ARs use different parameters for the final design. These parameters can be the location, position, speed, brightness, and specific embedded sensor outputs. The developer can determine the specific parameters to show up on the design . This category is also considered as a navigation system. For example, when the user wants to go somewhere this application can show the direction with 3D arrows on the road like video games.
Projection-based AR works with projection. Projection lights reflect the virtual design on a surface. If the expected vision is not where it should be, programs decide the specific case. For example, for the 3D keyboard design projected on a surface, when the user presses a specific key on the AR keyboard an algorithm detects corruptions of light. Then the application sends the information to the computer of which key has been pushed. These categories are used by laser plasma technologies for 3D design holograms.
Superimposition-based AR looks like a combination of the marker and markerless AR. The markers provide the algorithm inputs and the programs create new markerless outputs. Ikea augmented furniture application is a good example of this . When a user scans furniture on the catalogue with a camera, algorithms create the 3D model of the scanned objects and the user can place this 3D object anywhere. The markerless component uses GPS and accelerometer sensors, thus when the specific object place is placing, it saves this location and you can view the object from all angles.
AR utilizes cameras and sensors to gather information about checking a certain case, and if this case occurs it starts to process. In the processing step, AR algorithms use CPU, GPS, and Bluetooth/Wi-Fi data. Then it checks the conditions pre-determined and coded by the developer. If any case happens outputs also change.
 “The Ultimate Augmented Reality Technology Guide.” Reality Technologies, www.realitytechnologies.com/augmented-reality.
 “Augmented Reality.” Wikipedia,