Define simple harmonic motion and write its important characteristics.

(N/A) Simple Harmonic Motion $(SHM)$ is defined as the periodic motion of a body about a fixed point on a linear path,where the restoring force acting on the body is always directed towards the fixed point (mean position) and is directly proportional to the displacement of the body from that fixed point.
Mathematically,this is expressed as $F = -kx$,where $F$ is the restoring force,$x$ is the displacement from the mean position,and $k$ is the force constant.
Important characteristics of $SHM$:
$1$. The motion is periodic and oscillatory.
$2$. The restoring force is always directed towards the mean position.
$3$. The magnitude of the restoring force is directly proportional to the displacement from the mean position $(F \propto x)$.
$4$. The acceleration of the particle is also proportional to the displacement and directed towards the mean position $(a = -\omega^2 x)$.
$5$. $A$ body performing simple harmonic motion is called a Simple Harmonic Oscillator.