If you have an overhead garage door at home, it most probably uses one or more galvanized torsion springs. These components are responsible for counterbalancing the weight of the door. That is why each one is loaded with torque. During the opening of the door, this torque is released and applied to the drums and then to the cables. This is how the spring actually enables the lifting of the unit. The opener plays only a small part.
These particular springs are made with the use of galvanized steel wire. This type of steel is resistant to rust and corrosion and this makes it a popular material not only for hardware parts, but for different kinds of structural components as well. As its name suggests, it is made with the use of a process called galvanization. During the process, the wire made from regular steel is dipped into molten zinc. This is how it receives zinc coating. This coating prevents air and water from getting into direct contact with the more vulnerable metal underneath. This is how it provides protection.
While air and water cannot damage the zinc coating, there are compounds that are capable of doing this. They are found in some cleaning products. That is why you should refrain from cleaning the spring with any type of solution apart from solvent which is recommended or approved by the door's manufacturer. Similarly, you should avoid cleaning the wall next to the component with commercial products that may pose threat to it.
However, due to the great amount of work which they do, they are subject to a high rate of wearing. This means that they will break eventually and when this happens, immediate replacement will be required.