Afterimage is a computer graphics

Computer graphics

Computer graphics are graphics created using computers and, more generally, the representation and manipulation of image data by a computer with help from specialized software and hardware....

 effect used by computer games

Computer Games

"Computer Games" is a single by New Zealand group, Mi-Sex released in 1979 in Australia and New Zealand and in 1981 throughout Europe. It was the single that launched the band, and was hugely popular, particularly in Australia and New Zealand...

. The effect takes the bright parts of a rendered image of the scene, and then fades in a motion blur

Motion blur

Motion blur is the apparent streaking of rapidly moving objects in a still image or a sequence of images such as a movie or animation. It results when the image being recorded changes during the recording of a single frame, either due to rapid movement or long exposure.- Photography :When a camera...

 style fashion as the scene progresses. The result is that bright areas leave a fading trail when the camera is moving. Afterimage can be used to enhance blooming

Bloom (shader effect)

Bloom is a computer graphics effect used in computer games, demos and high dynamic range rendering to reproduce an imaging artifact of real-world cameras. The effect produces fringes of light around very bright objects in an image, obscuring fine details...

. In some games, the process is named light trail.