In a block-spring model of simple harmonic oscillation, amplitude and displacement are related but distinct concepts.
Amplitude refers to the maximum displacement from the equilibrium position in a vibrating system. It represents the maximum distance the object or particle moves from its equilibrium position during the oscillation. In other words, it measures the "extent" or "magnitude" of the oscillation. The amplitude remains constant throughout the motion unless external factors or damping affect the system.
Displacement, on the other hand, refers to the position of the object or particle at a particular instant in time relative to its equilibrium position. It is the distance and direction of an object or particle from its equilibrium position at any given time during the oscillation. Displacement can be positive, negative, or zero, depending on whether the object is displaced to the right, left, or at the equilibrium position, respectively.
To summarize, amplitude is a measure of the maximum extent of oscillation, while displacement refers to the position of the object at a specific moment in time relative to its equilibrium position.