Something fundamental is basic, essential, and foundational. It's the kind of thing that everything else depends on or builds from. Reading is a fundamental skill because you need it for almost every subject in school. In basketball, dribbling and passing are fundamental skills that players must master before they can execute complex plays.

When scientists talk about the fundamental laws of physics, they mean the deepest, most basic principles that explain how the universe works. When someone says, “Let's get back to fundamentals,” they mean returning to the core ideas or basic techniques that matter most.

Just as a building's foundation supports everything above it, fundamental ideas support more complex thinking. In music, you learn fundamental techniques like how to hold your instrument and read notes before attempting difficult pieces.

Sometimes people use fundamentals as a noun to mean the basics: “She's still learning the fundamentals of cooking” means mastering essential skills like chopping vegetables, measuring ingredients, and controlling heat. Whether in sports, academics, or any skill, the fundamentals are what you absolutely need to know first.