"Dental Implants Net" is an information site aimed at providing a better public understanding and popularization of dental implants.
Platform switching is simply using an abutment that is smaller than the implant. Not all systems will allow you to do this. The reason that it is supposed to work is because it reduces the microgap, thus reducing bacterial induced bone loss.
The goal of platform switching is to prevent the normal bone loss down to the first thread that occurs around most dental implants, thus enhancing soft tissue aesthetics and stability.