The essential philosophy of Web 2.0 seems to be user generated contents. The position of user has changed from consumer to participant. The flow of information has gone in one direction for a long time. It has been controlled by the mainstream media organizations in the era when we have grown up. But essential change or idea of Web 2.0 is that the information or contents are not given by someone privileged any more. Rather, information and contents are generated and shared together by individuals. In other words, this change is from read -only to read-write. Now all of us can become writers.

The concept is  the web as platform rather than the web as product. The business model of Web 2.0 offers services, not packaged softwares. It might be a sort of community. Its policy should be harnessing collective intelligence. It is supported by the trust to users as co-developers. When users involve in the platform, which might be a service or a community, they feedback their information, idea, opinion to it. Then, the original shape of the platformed will transform into something new by interference of users. This process will improve the efficiency of the service.

Collective intelligence produced by Web 2.0 has a big potential. In a sense, it is the most democratic way than ever before. Intelligence which once owned by only one part of the society can absorb various kinds of information spread in the wide range of the society. It leads to the question about copyright.

The aggregation of  contents under Web 2.0 environment tends to be made by reuse of other’ s contents. Democratized technologies enable it. Using contents published on the web freely open the  world of creative reproduction. At the same time, the trend violates traditional intellectual property right, which means that the trend might interfere professional creative activities. Once creative activities become accessible to amateurs, the society might not be allowed to restrict them. Creative activities in the wholes society will not die but prosper. However, professional creative activities might die.