Typically, signed papers represent organizations, and the government has influence over them. Depending on the type of organization, the organization may or may not have shareholders.
Decentralized autonomous organization (DAO) is an organization that is represented by a computer program (that is, the organization runs according to the rules written in the program), is completely transparent, and has total shareholder control and no influence of the government.
To achieve these goals, we need to develop a DAO as a DApp. Therefore, we can say that DAO is a subclass of DApp.
Dash, and the DAC are a few example of DAOs.