Often, when we think of design, we think about how something looks. On the Web, the first matter of business is designing how the site works. Before picking colors and fonts, it is important to identify the site’s goals, how it will be used, and how visitors move through it. These tasks fall under the disciplines of Interaction Design (IxD), User Interface (UI) design, and User Experience (UX) design. There is a lot of overlap between these responsibili- ties, and it is not uncommon for one person or team to handle all three.
The goal of the Interaction Designer is to make the site as easy, efficient, and delightful to use as possible. Closely related to interaction design is User Interface design, which tends to be more narrowly focused on the functional organization of the page as well as the specific tools (buttons, links, menus, and so on) that users use to navigate content or accomplish tasks.