In general, distributed computing is any computing that involves multiple computers remote from each other that each have a role in a computation problem or information processing.
1) In business enterprises, distributed computing generally has meant putting various steps in business processes at the most efficient places in a network of computers. In the typical transaction using the 3-tier model, user interface processing is done in the PC at the user's location, business processing is done in a remote computer, and database access and processing is done in another computer that provides centralized access for many business processes. Typically, this kind of distributed computing uses the client/server communications model.
The Distributed Computing Environment ( DCE ) is a widely-used industry standard that supports this kind of distributed computing. On the Internet, third-party service provider s now offer some generalized services that fit into this model.
2) More recently, distributed computing is used to refer to any large collaboration in which many individual personal computer owners allow some of their computer's processing time to be put at the service of a large problem. The best-known example is the SETI@home project in which individual computer owners can volunteer some of their multitasking processing cycles (while concurrently still using their computer) to the Search for Extraterrestrial Intelligence ( SETI ) project. This computing-intensive problem uses your computer (and thousands of others) to download and search radio telescope data.
One of the first uses of distributed computing was the breaking of a cryptographic code by a group that is now known as distributed.net.