eXternal Data Representation Protocol

The eXternal Data Representation (XDR) protocol is the specification for a standard representation of various data types.

By using a standard data type representation, a program can be confident that it is interpreting data correctly, even if the source of the data is a machine with a completely different architecture.

In practice, most programs do not use XDR internally. Rather, they use the data type representation specific to the architecture of the computer on which the program is running. When the program needs to communicate with another program, it converts its data into XDR format before sending the data. Conversely, when it receives data, it converts the data from XDR format into its own specific data type representation.