Web sites can be created with either a static or fully dynamic architecture. Static Web sites consist of HTML pages that combine content (words, numbers, and images), logic (how the content is manipulated), and presentation (colors, layout, fonts, and formatting). In HTML, there is only limited capability to manage or change the content separately from the way it is manipulated or presented. Managing and changing the material requires working with content and HTML tags directly within each of the pages. Static sites are usually easier to develop than dynamic Web sites, but can become much more costly to maintain and manage as they increase in size. Dynamic Web architecture, in this case based on XML, provides the ability to greatly simplify the management, evolution, and expansion of a Web site by providing control of the logic and presentation independent of the content. For example, users can be presented with information based upon their individual preferences, such as larger fonts for a visually impaired person. The site can also be made much more interactive. Dynamic Web sites are generally more expensive to develop than static ones, but are cheaper to manage and maintain up-to-date content.