fundamentals

n. system of ideas or principals which serve as a base or foundation

n. principle, basis, essential; fundamental note, lowest note of a chord (Music)

The fundamental tone, often referred to simply as the fundamental and abbreviated fo, is the lowest frequency in a harmonic series.The fundamental frequency (also called a natural frequency) of a periodic signal is the inverse of the pitch period length. The pitch period is, in turn, the smallest repeating unit of a signal. One pitch period thus describes the periodic signal completely. The significance of defining the pitch period as the smallest repeating unit can be appreciated by noting that two or more concatenated pitch periods form a repeating pattern in the signal. However, the concatenated signal unit obviously contains redundant information.
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Noun
1. principles from which other truths can be derived; "first you must learn the fundamentals"; "let's get down to basics"
(synonym) basics, fundamental principle, basic principle, bedrock
(hypernym) principle
(hyponym) rudiment, first rudiment, first principle, alphabet, ABC, ABC's, ABCs

Noun
1. the lowest tone of a harmonic series
(synonym) fundamental frequency, first harmonic
(hypernym) harmonic
Adjective
1. serving as an essential component; "a cardinal rule"; "the central cause of the problem"; "an example that was fundamental to the argument"; "computers are fundamental to modern industrial structure"
(synonym) cardinal, central, key, primal
(similar) important, of import
2. being or involving basic facts or principles; "the fundamental laws of the universe"; "a fundamental incompatibility between them"; "these rudimentary truths"; "underlying principles"
(synonym) rudimentary, underlying
(similar) basic
3. far-reaching and thoroughgoing in effect especially on the nature of something; "the fundamental revolution in human values that has occurred"; "the book underwent fundamental changes"; "committed the fundamental error of confusing spending with extravagance"; "profound social changes"
(synonym) profound
(similar) significant, important

the basics, as of a business e.g. product portfolio offered, USPs, staff skills, market growth, level of competition etc.