The meaning of FUNDAMENTAL is serving as a basis supporting existence or determining essential structure or function : basic.

The fundamentals include modularity, anticipation of change, generality and an incremental approach.

FUNDAMENTAL definition: serving as, or being an essential part of, a foundation or basis; basic; underlying. See examples of fundamental used in a sentence.

Bedrock is literally a hard, solid layer of rock underlying the upper strata of soil or other rock. Thus, by extension, it is any foundation or basis. Used literally as early as 1850 in Nelson Kingsley’s Diary, the …

a principle, law, etc, that serves as the basis of an idea or system: teaching small children the fundamentals of road safety the principal or lowest note of a harmonic series

The fundamentals of something are its simplest, most important elements, ideas, or principles, in contrast to more complicated or detailed ones.

Reading, writing, and arithmetic are the fundamentals of education.