Balance

 

• formal, conventional and mirror-image which is symmetrical balancing, here's an example:

 source: http://blog.visiondecor.com/index.php/2009/06/05/going-on-an-interior-design-adventure/

• in-formal, dynamic, non mirror-imaged but balanced, objects in either side of the room would be different in size and proportion which is asymmetrical balancing

source: http://gladyshunziker.hubpages.com/hub/Contemporary-Living-Room-Design-Creating-Balance-without-Symmetry

• radial balancing which revolves around an object in the center, which is not so popular

source: http://adesignersworld.blogspot.com/2010/08/interior-design-101_23.html