The most common being the 3 blade system from Gillette the Mach3 and the 5 blade Fusion Razor.
The three blade Mach 3 from Gillette allows for a shave with less pressure on the skin and with fewer strokes, this in turn helps reduce cuts and skin irritation. The swivel head follows the skins contours helping you to get that closer shave.
The 5 blade Gillette Fusion shaving surface creates less friction and therefore less irritation than the Mach 3 blade. 15 microfins follow the skins facial contours. Also incorporates a precision trimmer, a useful addition for straightening those sideburns.