Gliding is also reffered to as "Floating". From Wikipedia:
" Floating, gliding or sliding refers to a group of footwork-oriented dance techniques and styles closely related to popping, which attempt to create the illusion that the dancer's body is floating smoothly across the floor or that the legs are walking while the body travels in unexpected directions. ..."
"...Gliding uses the float technique but also adds a push and a pull to cause the feet to glide over the floor, taking up more space and creating a bigger illusion. Gliding can be performed in many directions, but most common are the sideglide and the circleglide."
With respects, Michael Jackson basically perfected the art of gliding with his "Moonwalk" move. a good show of it is here: http://www.youtube.com/watch?v=-tqYUTjQIc0
Floating Wikipedia: http://en.wikipedia.org/wiki/Floating_%28dance%29