Data Exchange
One of the more effective methods used to transfer data among applications, clients, and sites is the Dynamic Data Exchange (DDE) protocol. The DDE protocol is a set of messages and guidelines that primarily sends messages between applications that share data and use shared memory to exchange data between those clients and applications.

Use of DDE allows information to be shared or communicated between programs. For example, when a data element or information is changed in one place (a program or spreadsheet), using DDE insures that the data is changed everywhere else.

Clients can use the DDE protocol for one-time data transfers or for continuous streaming exchanges in which applications send updates to one another as new data becomes available.