ghosting 
1) A visual phenomenon in LCDs and other digital displays where an image moves faster than the display can redraw it, thereby leaving a trail of former versions of the image in the wake of the redrawn image Ghosting might also be called trailing or streaking. As LCDs evolve, faster pixel-response times are reducing the ghosting problem.

2) In television and in flat-panel displays such as LCDs, a shadowy ghost of a displayed image that may appear due to signal interference. DTV broadcasts can suffer from ghosting, which is sometimes called multipath.

3) CRTs that display the same image for a long period of time will eventually develop a permanent shadow burned onto the screen, called a ghost. The advent of screensavers has helped reduce the occurrence of ghosting.