The definition of a reference frame in general relativity is achieved through the
construction of a congruence of time-like world-lines. In this framework,
splitting techniques enable us to express physical phenomena in analogy with
special relativity, thereby realizing the local description in terms of Minkowski
spacetime in accordance with the equivalence principle. This approach holds
promise for elucidating the foundational principles of relativistic gravitational
physics, as it illustrates how its 4-dimensional mathematical model manifests
in practical measurement processes conducted in both space and time. In
addition, we show how, within this framework, the Newtonian gravitational
force naturally emerges as an effect of the nongeodesic path of the reference
frame.