The coefficient of d β d t {\displaystyle {\frac {d\beta }{dt}}} will be called the 'damping' by analogy with a mass-spring-damper which has a similar equation of motion. By the same analogy, the coefficient of β {\displaystyle \beta } will be called the 'stiffness', as its function is to return the system to zero deflection, in the same manner as a spring.