Rule of Thirds: the guideline proposes that an image should be imagined as divided into nine equal parts bu two equally spaced horizontal lines and two equally spaced vertical lines.
Dominant Center of Interest: the object in focus is in the center of the photo so that your eyes are drawn straight to that object.
Framing: a technique used to focus the viewer's attention upon the subject.
Formal Balance: a photograph that is the same on both sides.
Informal Balance: a photograph that isn't the same on either side.