A vibrant array of little lines traveling in the horizontal or the vertical. A generic run of the mill cheap anime effect used almost everywhere. Essentially they are used to show that somthing is moving, or is moving very fast.
For example: say Mr.Immortal Vampire sword freak is going to cut off the arm of Mr.Mutant from 10,000 years in the future.
- Show Combat scene
- Show extreme close up of the combatants' faces (must be screaming)
- Show hero raising sword
- show still picture of blade, with motion lines zooming around in the background
- Show sword cutting through arm
- Show slow motion repeat of last item if needed
For a great example of motion lines, just watch
Vampire Hunter D