I've mentioned before what graphic design is, and what it isn't. And one of the most misunderstood difference is between visual communication and decoration.
Image courtesy of Sura Nualpradid at FreeDigitalPhotos.net
Too many people treat design like icing on a cake. The cake is all the carefully crafted words and sentences that communicate information, while the icing (or design) makes them look pretty. (But with this type of mind-set, I doubt that the carefully crafted words are crafted well.)
What's the difference?
When someone views design as decoration they tend to separate the act of design from the content. What I mean is that, for them, the content or text is suppose to do all the work of communicating, while design comes in later to make the message more appealing.
However, when someone views design as a communication strategy they tend to see the act of content-creation and the act of design as a symbiotic relationship, where each has a role, but each contributes to enhance and clarify the main message.
Another difference is that design as decoration is only concerned with the arrangement and selection of different elements such as fonts, colors, images, and so forth to make the page or item more appealing. The main purpose for this is to ensure that the content looks good (to the author).
On the other hand, design as a communication strategy uses the elements of design in conjunction with the overall message strategy. The reason for this is that the design and content are to work together to connect the viewer to the message emotionally, not just intellectually.
To sum it up, decoration is making information prettier. Strategic design is visual communication that impacts people.