A bit stream (English bitstream ) is a sequence of bits of indefinite length in a time sequence. It is the most superficial way of looking at a data stream, which is usually divided on closer inspection into logical structures. It is divided into the first rule in fundamental structures such as small icons fixed size - the bytes ( byte stream ) - and further into blocks and data packets of different protocols and formats.

On digital storage media and data transmission channels, the data is usually represented as a single data stream from a front, for example, electrical signal. Multiple data streams to provide reasonably available simultaneously, they are partially entangled multiplexers into one sequence and split on the other side of the corresponding demultiplexers again to be routed to different programs or devices.