What is the purpose of a garage door cable tensioner and how does it contribute to the overall functionality of a garage door system?

A garage door cable tensioner helps to keep the cables that lift and lower the garage door properly tensioned. This is important because it ensures that the door operates smoothly and safely. If the cables are not properly tensioned, it can lead to the door becoming misaligned or getting stuck, which can cause damage to the door and pose a safety risk.