Geothermal Ground Loops
The ground loop component of a geothermal system is basically a heat exchanger with the earth. Fluid is circulated through it to facilitate that heat exchange between the earth and your home. During the summer, heat is taken from the house, put in the circulating fluid in the ground loop, and then expelled into the ground. The winter is the exact opposite.
All ground loops only serve that function, to be a heat exchanger for the system. The loop type is mainly dependent on the location of the system (soil type, land available, static water level, etc). Each have their advantages and disadvantages, and you will have to meet with us to determine which one will work the best in your situation.