What are transformers used for in pond lighting?

i have a little pond and i want to light up the waterfall and i was wondering what transformers are used for... Please help me. thanks!|||The transformers are 12 volt systems and thus a user friendly system. They can be installed by the home owner. A 120 volt system has to be installed by an electrician. You use the same transformer as any other landscape light system.|||i think it changes the house current to one like battery. from AC current to DC. but purpose is to lower the wattage flowing through the wires so if it gets a connection to water it won't electrocute everyone. like if u were swimming or had cut through the wire on accident.





u get the size transformer based on how many watts of lights/equipment you want to run.





here is a place that can give you advice how to do things if u need two-way discussion:


http://www.homerepairforum.com/forum/





and more places like that;


http://www.dmoz.org/Home/