Question

A mass hanging from a spring undergoes vertical simple harmonic motion

Answer 1

Pendulum movement is a right type of periodic motion called simple harmonic motion.  

Position of the moving object changes along with time.  

Many objects moves back and front.

Movement of child on swing can be exactly be sinusoidal and can be taken into account as simple harmonic motion.  

Few difficult movements(motions) i.e. heavy waves of water aren't taken as a simple harmonic motion.

Any object is in simple harmonic motion when rate at which it oscillates from this side to that and its position with time can be easily verified.