What is Asynchronous communication?

Asynchronous communication is the exchange of messages, such as among the hosts on a network or devices in a computer, by reading and responding as schedules permit rather than according to a synchronized clock for both the sender and receiver or in real time. It is usually used to describe communications in which data can be transmitted intermittently rather than in a steady stream.

It is a data communications method in which bits are sent one after the other with a start and stop bit used for flow control. This is opposite to synchronous communication where blocks of data are transmitted using a synchronizing clock.

Most communications between devices within computers (between the CPU and disk drives) and between computers and external devices (modems and printers) are asynchronous. Asynchronous communications also include computer-based exchanges of messages for which the participants need not be available or online at the same time, but rather, read and respond as their schedules (and desires) permit.

In asynchronous communications it is necessary for the receiver to be able to distinguish between valid data and noise (random signals). In computer communications, this is usually accomplished through the use of special bits at the beginning and end of each message.

Asynchronous collaboration, such as email and document sharing, can certainly be used for day-to-day communications when an urgent response isn't needed. This sort of communication is suitable for sending out broadcast messages that don't necessarily need to be acted on immediately, or for corresponding with clients, customers, and business partners without putting pressure on them to respond immediately.