In the Windows, OS/2, and (with third-party development kits) other operating systems, Dynamic Data Exchange (DDE) allows information to be shared or communicated between programs. For example, when you change a form in your database program or a data item in a spreadsheet program, they can be set up to also change these forms or items anywhere they occur in other programs you may use. DDE is interprocess communication (IPC) that uses shared memory as a common exchange area and provides applications with a protocol or set of commands and message formats. DDE uses a client/server model in which the application requesting data is considered the client and the application providing data is considered the server.
Thousands of applications use DDE, including Microsoft's Excel, Word, Lotus 1-2-3, AmiPro, Quattro Pro, and Visual Basic.
Another facility, NetDDE, allows progams to converse across networks. For example, a Superbase program on one network node could be updated whenever an Excel program in network node was updated. Both nodes must have NetDDE installed.