Define the amplitude of $SHM$ and draw two different $SHM$s in one figure having two different amplitudes.

(N/A) Amplitude: The magnitude of the maximum displacement of the particle executing $SHM$ from its mean position is called the amplitude of the $SHM$.
The symbol for amplitude is $A$ or $a$,and its $SI$ unit is $m$. The dimensional formula is $[M^0 L^1 T^0]$.
The displacement of an $SHM$ particle oscillates between two extreme points $+A$ and $-A$.
The plot of displacement as a function of time with initial phase $\phi = 0$ for two different amplitudes is shown in the figure. The curves $1$ and $2$ represent $SHM$s with amplitudes $A$ and $B$ respectively,where $x(t) = A \cos \omega t$ and $x(t) = B \cos \omega t$.