In general, Web design is the planning and creation of websites. This includes the information architecture, user interface, site structure, navigation, layout, colors, fonts, and imagery. All of these are combined with the principles of design to create a website that meets the goals of the owner and designer.
A better definition and our philosophy:
Web design is the creation of digital environments that facilitate and encourage human activity; reflect or adapt to individual voices and content; and change gracefully over time while always retaining their identity.