Balance creates the perception that there is equal distribution.  This does not always imply that there is symmetry.

Variety means "to change the character" of an element, to make it different.

Emphasis creates a focal point in a design; it is how we bring attention to what is most important. Emphasis is what catches the eye and makes the viewer stop and look at the image. Without emphasis, without getting the viewer to look at the image, communication cannot occur.

Harmony in visual design means all parts of the visual image relate to and complement each other.

 Proportion refers to the relative size and scale of the various elements in a design. The issue is the relationship between objects, or parts, of a whole.

Pattern is an underlying structure that organizes surfaces or structures in a consistent, regular manner. Pattern can be described as a repeating unit of shape or form, but it can also be thought of as the "skeleton" that organizes the parts of a composition.

 Movement is the motion or movement in a visual image occurs when objects seem to be moving in a visual image. 

Rhythm is the repetition or alternation of elements, often with defined intervals between them.
Rhythm can create a sense of movement, and can establish pattern and texture. There are many
different kinds of rhythm, often defined by the feeling something evokes when viewed.