The lubrication strip on your Gillette razor, found above the blades in your cartridge, can be compared to a small sponge
The strip holds a formula with water-loving polymers called Polyethylene Glycols (PEGs) which are released from the strip with each shaving stroke. When these polymers come into contact with water, they swell, unfold and stretch along your skin, adding lubrication to your shave.
The effectiveness of the shaving cream can be diminished when we go over the same spot on our face more than once, over and over again, in an effort not to miss any hairs, with shaving cream having been wiped away. This leaves the skin less protected and can lead to razor burn.