In old days libraries were important because they were about reading. They were often built as cultural statements, rather than as useful and accessible places of reading. In some cases, the size and architecture mattered more than the function of the library. In the modern information society libraries have a new role and there are various types of library models. In the modern information society, where the use of electronic services and Web-based information sources constantly increases, libraries are managed in a more democratic way, have more flexible communication system and work organisation, and their service development is based on the quality and user-orientation of services. To be successful, the libraries should pay more attention to the development trends of information society that would enable to adjust their development strategies to social information needs. For that reason it is important to see library as a part of social model of the society and its role in social development plans and strategies and in legislation.