Java 1.4 Game Programming (Wordware Game and Graphics Library)

A stream is simply an abstract representation of a physical input or output device. A stream can be thought of as a pipe that bytes of data flow through, and therefore data can be both read to and written from a stream.

As you have probably guessed, there are two forms of streams: input streams and output streams. Examples of input streams are a keyboard, disk file, or remote network application that is sending data. Examples of an output stream are a disk file, a console window, or even a printer.