Which term describes the natural process of how the moon's appearance changes over time?

The term that accurately describes the natural process of how the moon's appearance changes over time is "moon phases." This phrase specifically refers to the distinct stages the moon goes through during its orbit around the Earth, which include the new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter, and waning crescent.

Understanding moon phases is essential in various scientific fields, including astronomy and Earth science, as they reflect the interplay of sunlight, the moon, and the Earth. Each phase is defined by the position of the moon relative to the Earth and the sun, leading to varying amounts of the moon’s surface being illuminated from our perspective on Earth.

The other terms presented do not have the same established definition in astronomical nomenclature. "Moon cycles" may refer vaguely to the same concept, but it lacks the specificity and scientific clarity of "moon phases." "Lunar dynamics," while it sounds relevant, is more focused on the physical forces and motions affecting the moon rather than the visual changes in its appearance. "Cyclic lunation" is an uncommon term and does not have widespread usage among those studying the moon's phases, making it less recognizable in the context of this question.