Low voltage means that there is a transmitter, and transformer reduces the current from 120 volt to 12 volt. Some of low voltage system's benefits are:

Can be used in wet or moist locations
In most cases might not require local permit
There are flexibility in installing and relocating
In most cases any one can install
Landscape lighting is easy and safe to install, because it carries less power
The cable can be buried just below the surface, rather than in a deep trench
It is the most efficient way to light outdoor
They are more appropriate for residential properties