Visual design creates the mood, presents the ‘personality’ of your business and elicits an emotional response from your customers.
The visual design step is usually the most rewarding in the website design process, as it is when everything comes together.
Visuals for the web should be visually appealing, clean, minimal, and help the user to understand your content or message. In many ways the best visuals on the web are unobtrusive or "invisible" and help the user to move through the site to digest your message.
Visual design on the web is not just about making things look good. It should also be efficient to code, load quickly in the browser and accommodate varied content.