ABOUT THE SYMETRY

Symmetry: Is when some shapes are a reflection of other. It´s only on same shapes.
Reflection symmetry: Is a quality of same shapes that consists in having an axis between two shapes, and it's like when you see you in a mirror.
Symmetry axis: Is when a line divides in two symmetrical parts. Every element of the shape is represented in the other part at the same distance from the axis. Symmetrical points are on perpendicular lines to it.
Central symmetry: Its a reflection of a shape without an axis, so there is a symmetry centre. Every element of the shape is represented in the other part at the same distance from the symmetry centre. Symmetrical points are collinear with the centre.
Geometric symmetry: Is a kind of symmetry which follows accurately (presition9 the geometric symmetry rules.
Apparent symmetry: Is a quality of shapes or objectswhich shows an obvious symmetry, but not every elements follows this rules. It happens very frecuently in nature.

Symmetrical balance: Is a way to organize parts of an image, picture or drawing, so one side mirrors (duplicates) the other. The opposite way is called Asymmetrical balance.