Understanding follows intuition, inspiration and exploration. And it answers this question: "How do I....(solve this)?" Understanding composition and how it affects visual communication is empowering. Composition drives mood, meaning and message. It is the arrangement of things like line and color. In broader terms, composition is the arrangement of the elements of art according to the principles of design. The elements are: line, shape, form, value, color, texture and space. The principles of design include: unity, contrast, emphasis, balance, pattern, rhythm and movement. Here, in simple terms is an introduction to composition.
Here is an introduction to LINE.