: Web usability is a common term used in discussions of WWW (World Wide Web). This is definitely important, as more and more web sites are frequently visited and have great impact in the new economy, the network economy. However, research lack in consistency in defining `web usability'. Some point out that the term is equivalent with the traditional term in HCI (Human Computer Interaction) research. Others point out the differences with traditional usability and do this with comparisons between the two. This article discusses the concept of usability in general as well as the notion of web usability and their relation. Further, a conceptual model is built to facilitate how to handle usability aspects on the web. This model is then exemplified with two examples of web sites. Here, the importance of choosing the right categorization is clear. The sites are both e-commerce sites, however, they show upon clear differences when it comes to usability aspects. Web usability is an importa...