Basic vs. Fundamental What's the Difference? Basic and fundamental are two terms that are often used interchangeably, but they have slightly different meanings. Basic refers to something that is simple, essential, or fundamental in nature. It implies a foundational level of knowledge or understanding. On the other hand, fundamental refers to something that is essential, crucial, or necessary for the existence or functioning of something else. It suggests a deeper level of importance or ... FUNDAMENTAL meaning: 1. forming the base, from which everything else develops: 2. more important than anything else…. Learn more. Learn the meaning and usage of the word fundamental , which can be an adjective or a noun. Find synonyms, antonyms, translations, and related terms for fundamental in different contexts. Fundamental is a word that can refer to various concepts in different fields, such as reality, frequency, religion, mathematics, music, and more. It is also the name of several books, albums, and a TV show episode.