Symmetrical or Formal
Balance through likeness; identical visual elements arranged evenly; left to right in mirrored positions on either side of a central vertical axis
Asymmetrical or Informal
Balance through contrast; dissimilar elements of equal visual weight or eye attraction balanced through contrast by position, different shapes, values, colors, textures, etc.
All elements radiate out from a common central point creating an obvious focal point.
Equal emphasis over the entire area; the same visual weight or eye attraction everywhere.