A retaining wall is a structure used to stabilize sloping ground and hold it in place. The wall is also used to prevent movement of the ground and any associated soil erosion. A retaining wall has to be big and sturdy enough to hold back the soil and redistribute the forces caused by the sloping ground.
Since the retaining wall will become part of the landscape, working with a landscape design company can help it enhance the look of your home as well as stabilize the sloping ground. Adding plants and other garden features will make the retaining wall look like a natural part of the landscape. In this way the retaining wall will be able to do its job and blend into your yard design.
Retaining walls can be built out of various materials including stone, concrete, wood. Each material has advantages and drawbacks in given situations, and that's why it is best to consult a professional when contemplating building a retaining wall. Generally, if a wall is more than knee high or a few courses in height the best thing is to call an expert to help with the design and construction of the structure.