Unity is the underlying principle that sums up all of the principles and elements of design.
Unity refers to the combination of all elements successfully working together to achieve a
sense of harmony in your design. This can be achieved through the consistent use of graphic elements.
Using repetition or patterns is one of the most basic factors in creating a strong sense of unity.

The principle of alignment focuses on the placement of graphical elements and their relationship to
each other and as a whole (Gestalt Theory).
Alignment allows a visual connection with elements in your design to be formed
even if they are not close in proximity.
Alignment helps to create unity and balance.

Balance is the concept of visual equilibrium.
It is the combination of opposing elements in a composition that results in visual stability.
Most successful compositions achieve balance using symmetry or asymmetry.

Symmetry refers to the organization of elements in which a balanced visual hierarchy is achieved
through the alignment of graphics along a horizontal or vertical axis.
This means that your design can be reflected precisely over a central axis like a mirrored image.

Asymmetrical
In contrast, design elements that display an unbalanced visual weighting that are made up of elements differing in size,
color and shape are organized and positioned against one another to create asymmetry.