asynchronous input/output (AIO)

Asynchronous Input/Output (AIO) is one of two basic modes of operation for a given input/output stream. The other is Synchronous Input/Output.

In asynchronous operation, the physical input/output changes are not necessarily synchronous with the program states. Thus, in asynchronous operation, texts can be entered via the keyboard, which are not immediately shown on the display but are stored in a buffer. During output, data can be buffered and transferred to a memory together.