The spring rate is a measure of how much a spring compresses or extends under a given load. It is typically expressed in units like pounds per inch (lb/in) or newtons per millimeter (N/mm). A higher spring rate means the spring is stiffer and requires more force to compress, while a lower spring rate indicates a softer spring that compresses more easily. Spring rates are crucial in various applications, including automotive suspension systems and machinery. In vehicles, the right spring rate helps maintain proper ride height and comfort, ensuring that the suspension can absorb bumps effectively while providing stability during driving.