Low voltage wire does not need to be run through conduit.  A low voltage system is flexible.  You can easily move fixtures to accommodate plant growth or to change lighting effects.

Low voltage systems are safe and energy efficient.   Transformers reduce standard voltage from 120 volts to a safe 12 volts.  There is no risk of electrical shock to children or animals if the cable is accidentally cut.  Lamps use less energy yet provide comparable performance to many 120 volt, higher wattage lamps.

Line voltage (120 Volt) systems are used where brilliant illumination is required for safety or security, for lighting large areas, or for spots where you must light from farther away, such as up lighting huge trees.  In many cases, a landscape lighting design can be developed using both line voltage and low voltage components.