distributed data processing (DDP)
The logically and physically close connection of centralized and decentralized data processing generates a scenario with great potential: the distributed data processing operating mode.
Distributed data processing must find its realization in a suitable combination of hardware, operating systems, networks and their protocols, and finally application software. A computer system for distributed processing consists of several computers coupled together, where the main task of the operating system is to organize the distribution of data, resources and workload.
In connection with distributed data processing, larger companies and organizations often follow the concept of three computer levels: the workstation computer level, departmental computer level and the mainframe computer level.
The workstation computer level is characterized by end devices such as personal computers(PCs) or workstations and by networking. The departmental computer level knows servers, minis and small mainframes that provide the workstation computers with application-related and infrastructural power, and the mainframe level consists of one or more mainframes that provide services that cannot be provided by the other computer levels for various reasons.