Many different people exchange terms when talking about the fundamentals of traditional visual art. The way people use the terms, or even how different sources define the terms, can often make it seem confusing. But don't worry, the concepts behind them are what's most important. I have a little breakdown for you here:
-Composition Fundamentals: Color (How you choose to use or not use color), Form (an object in 3D space), Line (how heavy or thick a line is), Space (the space inside or between objects in a work), Texture (Visual or literal texture in a work) and Value (The scale of how dark or light a work is).
Principals of Design
Balance: Equilibrium. The distribution of visual weights on each side of a vertical or horizontal axis (that offset one another).
Emphasis: The focal point. Prominence of “objects” in a work by use of force or intensity of expression to show that this “object” is important. The thing which first draws your eye.
Movement: The quality of representing or suggesting motion, the way you guide a viewer’s eyes throughout your work.
Proportion: Size relationship between “objects” in a work.
Rhythm: Repetition of lines shapes colors that create a “beat” just like in music. A characteristic pattern.
Unity: Harmony. The feeling that a piece is complete, wherein all the parts make one cohesive whole.
Pattern: The bones of a composition that helps define and organize separate parts into a whole shape. It can be repetitive such as one you see on fabric or purposefully broken up.
Pattern is an underlying structure that organizes surfaces or structures in a consistent, regular Space: The distance between objects in a work which can be positive (the space seems to be filled with something) or negative (the absence of an object), the space can also be open or closed, shallow or deep, and two-dimensional or three-dimensional.
Variety: The juxtaposition of separate or unrelated elements to compliment one another or cause visual dissonance.
I hope that helps! Good luck.