  In this paper we pose two fundamental ideas on the motion of an elementary
particle supporting the internal "spin motion" or $\textit{Zitterbewegung}$ and
a particle as concentrated energy. First, the particle moves randomly in a
limited area (in a quantum sized-volume) like random vibrating system where the
particle will diffuse in a quantum-sized volume when it absorbs or emits the
quantized amount of energy. The quantum sized-volume can move too and plays
role similar to the carrier amplitude, while the vibrational motion of the
fundamental particle with frequency and amplitude represents a modulating
signal. The current of diffusion process taking place in the quantum
sized-volume will represent the emergence of a spin phenomenon shown by the
existence of Clifford algebra. Second, the particle is pure energy concentrated
on the surface of 3 dimensional sphere-form (2-manifold without boundary).
Afterward we show that by defining the particle mass as an invariant quantity
based on the two fundamental ideas, we can derive both the diffusion constant
of the particle in the quantum sized-volume as $\beta = \hslash/2m$ and the
Schr\"{o}dinger equation. Furthermore, by posing that the vibrational motion of
the particle limited on the quantum sized-volume plays fundamental role as time
interval unit (proper time or particle clock), we show that the relativistic
effects of the particle must represent atomic processes.
