A data transmission method in which each character sent is preceded by a start bit and followed by a stop bit. These framing bits tell the receiving device that the bits between them constitute a code for a character.
A form of communication by which applications can operate independently, so that they do not have to be running or available simultaneously. A process sends a request and may or may not wait for a response. It is a non-blocking communications style.
A communications system where the transmitter and receiver run independently. The beginning and end of the data packet are usually indicated by start and stop bits in the data stream.