What is the spring constant? On what factors does the work done by a spring depend?

(N/A) The spring constant $(k)$ is a measure of the stiffness of a spring. It is defined as the force required to produce a unit extension or compression in the spring. According to Hooke's Law,$F = -kx$,where $F$ is the restoring force,$x$ is the displacement from the mean position,and $k$ is the spring constant. Its $SI$ unit is $N/m$.
The work done by a spring when it is displaced from position $x_1$ to $x_2$ is given by the formula: $W = -\frac{1}{2} k (x_2^2 - x_1^2)$.
From this expression,we can conclude that the work done by a spring depends on:
$1$. The spring constant $(k)$,which represents the stiffness of the spring.
$2$. The initial position $(x_1)$ of the spring.
$3$. The final position $(x_2)$ of the spring.