Whenever we create design and art we are composing. Composition is the make up, arrangement or structure of a work, whether it’s music, writing, or visual art. Composition is often used interchangeably with the word design.
Composition sits on top of structure and is the visible result of planning and arranging a space. Structure is the foundation or framework that we hang things on. In art and design, we deal with principles of composition and compositional stress, and composition is supported by a formal or informal structure.
Structure begins with the frame of reference, or the picture plane. When we compose a drawing, illustration or design, we first begin with the space and its proportions. Portraits are often composed on a vertical structure. Film, video and television are composed on a horizontal structure. Images on Pinterest are vertical, Twitter favors horizontal graphics and Instagram is a square format — a structural shape with a 1:1 proportion or ratio.

Psychological Aspects of Composition
We can create different moods and messages simply in how we create structure and relate composition to it:
Horizontal structure with a horizontal composition: calming, peaceful, restful, pastoral.
Horizontal structure with a vertical composition: sturdy, static. The relationship of the horizontal and vertical create a cruciform configuration in which the directions cancel each other.
Horizontal structure with a diagonal composition: active, energetic, motion. Any diagonal conveys a sense of action.
Vertical structure with a vertical composition: monumental, worshipful, heroic, stabile
Vertical structure with a horizontal composition: serene, focused, static
Vertical structure with a diagonal composition: highly dynamic, active, off-balance.
Whether you’re designing a page layout or an illustration, you can use any of the combinations. The idea is to use the elements in order to help communicate your idea, story or message. An illustration of an automobile is more expected as horizontal structure, horizontal composition. It is also static. Place the car on a diagonal axis in a vertical composition and you communicate speed and movement, maybe even danger.
Consider these structural variations using the same composition:
Some Design Tips
Always compose your layouts and illustrations with the intended purpose in mind. What do you need to communicate? What structure makes the most sense given the use of the work? What compositional stress is most appropriate for the message? How will your design or illustration work across a variety of uses: web site, printed book, ebook?