This diploma thesis deals with ERP systems and web information systems such as ERP. The theoretical part describes the historical development of information systems and the inclusion of web information systems in the context of historical development. Analysis of existing ERP systems is followed by a section dealing with the current coverage of business processes by ERP systems and general recomended criteria for choosing information systems. The practical part contains a survey of perceptions of web information by organizations. The survey is conducted using questionnaires, which were interviewed randomly selected medium-sized and small organizations. The second part contains a comparison of classical information systems such as ERP with thick client with a web information system with thin client. These systems are compared using a multi-criteria analysis.