Design is how you communicate an idea to your users at a glance, without reading.
In some places, you could see a single word, symbol or logo, and instantly have a concept in mind of what you could expect.
With the use of iPhones and small devices, it is important to be space efficient and communicate your services at a glance. Consider the bird from Twitter, the bitten apple from Apple, and the open box from Dropbox.
In our fast paced world, you have about half a second of someone’s attention, and in that half a second, you must convince your viewer that you have what they are looking for, that they have come to the right place. Your Design should make an impact or an impression even before they start reading the content.