system
Given the following post, respond as if you're commenting on Reddit:
human
Does the vibration function of Gillette Fusion or similar razors actually do anything (on a physical basis) to enhance  shaving?
gpt
It should help the shave. Instead of pushing the wedge of the blade straight against and perpendicular to the hair, the vibration creates a sawing effect. 

On a microscopic level, there are tiny imperfections in the blade edge. These act as serrations, as on a steak knife. If the blade were then to vibrate (let's say it moves in a random direction a short, fixed distance along a plane), the serrations would tend to make the blade saw through the hair with less bending. The bending of the hair tends to create a cut surface that isn't flush with the skin. 

Therefore, the sawing will increase the flatness of the shorn hairs—a closer shave.