Garage doors tend to take a lot of abuse as one side is part of your home's exterior, subject to the outdoor weather conditions, and the other side isn't exactly a finished interior room but rather tends to smell like car exhaust, dirty pets, and your child's athletic gear. The door is opened and closed multiple times every day and isn't generally treated very gently. All of these circumstances are fine, the door is designed for such use, but it does lead to an ongoing need for maintenance and repair.
Spring and Cable Replacement
Springs, cables, and chains are an integral part of your garage door's function as they allow the door to be opened and closed mechanically whether you push a button in your car or on the wall in the garage. These parts manage a lot of stress every day, but unfortunately they wear out or break over time. It's part of the design as it is much less expensive to replace a broken cable than to replace the motor which opens the door, and it's far more convenient to replace the tensioned spring than to lift the weight of the door by hand every time you want to open or close it.
Garage Door Openers
Garage door openers are not created equal. Some brands are simply manufactured better than others, but beyond that concept each opener is designed for a specific use. Metal, vinyl, and wood doors have different weights and of course a two car garage with a single door has different needs than a two car garage with two doors. In spite of the manufacturer's recommendations for a garage door opener, a contractor who specializes in garage door installation and repair has the experience to know which one will work best for your specific situation.
Although the weight of the door is the most obvious consideration, there is also the fact that different door systems use different spring tensions to counterbalance the weight of the door, and there are different cable and chain sizes for the actual procedure of opening and closing the door. The height of the ceiling in your garage can be another factor in determining the load your garage door opener needs to handle. The amount of use the door sees can vary based on whether you park your daily car in the garage, store a boat or motorcycle in the garage, or use it for crafts and hobbies.