The figure displays two simple harmonic motions. Which parameter...

From the given figure, we can observe the following for the two simple harmonic motions A and B:

1. Both motions have the same maximum displacement from the mean position, which means their amplitudes are equal.
2. Both motions complete their respective quarter cycles in the same sequence of snapshots, indicating that their time periods and frequencies are the same.
3. Since the amplitude $A$ and angular frequency $\omega$ are the same, the maximum velocity v_{\text\max} = A\omega is also the same for both motions.
4. At the initial position, the particle in motion A is at the mean position and moving towards the right (positive direction), corresponding to an initial phase of $0$. In contrast, the particle in motion B is at the mean position but moving towards the left (negative direction), corresponding to an initial phase of $\pi$.

Therefore, the two motions differ only in their phase.