There are two main types of springs which are used in garage doors.
Extension Springs: These springs extend when the door is lifted, that provides a counterbalance to the door’s weight. These kinds of springs need a perfect one to one match in order to properly work and balance the door, making it crucial for quality work and parts.
Torsion Springs: The Torsion Springs twist inside to create torque, which in return is used to lift the weight of the door. While installing these kinds of springs, their size needs to be precisely measured and calculated to fit the door perfectly.